Random thoughts on the topic (TLDR Stuff, read at your own peril; you have been warned)
I'm going to disagree on the previously aforemetioned 'better' Atlas builds, simply for the fact that regular PPCs on a brawler is bad, and you should feel bad, and the sustainable dps plummets swapping the extra DHS for Endo. This is an argument though that I don't think will help the OP out at all. It's been going on since the break of the BT universe.
As far as DHS > SHS. This is true. The ONLY exception to the 'Always upgrade DHS, always' rule, in my most humble opinion, is in the very rare situations where you are running practically or quite literally heat neutral. Locusts aren't exactly considered awesome, but if you go with just an 'improved' 1V (Quad Mguns, MPlas), it sits at roughly a 1.9 heat rating with SHS. I really, really am not going to suggest someone drop 1.5mil to eke out an extra tenth of a heat rating. But that's it, anything that can run 1.8 or better with SHS, that's it, if you can't even see 1.5 with SHS, upgrade to DHS.
As far as building a 'mech goes; First and foremost, a little research. While grinding c-bills to make that 'mech purchase, check the stat charts on Smurfy's. Some 'mechs have better ranges of motion (Great to consider if you want to brawl with something), others (but not many), will have differing engine caps, affecting how fast you can go, how well you can maneuver.
Forums. Filllllled with suggestions and concept, and arguing. But take it all with a grain of salt. But this is more or less the best place you're going to find to figure out if the rig you're wanting to buy is going to fit the role you envision. Thinking a Locust 3S could make a good missile boat? (Don't, don't ever do that), maybe a rig with only two energy points would be viable as an energy sniper? (Might be it has low hanging arms and now jumpjets. i.e-not a good energy sniper).
All the blah blah stuff aside;
You've picked the role you want to fill.
Are you going to be backline, mid-range, or frontline? This determines if you should be 'lightly','moderately', or 'heavily' armored. This is just a heuristic, if you don't feel you have enough armor, you don't have enough armor. Now, if you consistently leave matches with parts that never get touched, or never go down to the internals....there might be too much armor there. (What? that's contradictory to what you just....ohhhhh)
Endo
...I'm in the 'not always the best option' camp. But I'm also in the 'experience will tell you when not to use it' camp. Some rigs it's darn expensive to upgrade to Endo. Personally, Assaults are a 'hand-waggle' situation. I see all that tonnage, I'm trying to cram firepower in it. Endo is going to get in the way of items that need a lot of crit space. To compound the issue, the big engines they need usually have an adequate number of heatsink/slots to keep the rig decently cool. But maybe not cool enough for your liking or skill level. Victor and Void already both posted some builds up that show the sacrifices you make for Endo over Efficiency. You get more bang, but don't get to use it as much (i.e- less sustained dps, less heat efficient). BUT, that doesn't mean don't Endo. If you're good at using cover, and engaging in 'bursts,' you can eat that, because you're likely fighting in alphas, not standing toe to toe. NOW, on the other hand, if you're keen on getting into toe to toes, those Victor builds are going to see you shutdown before your foe (or you should assume).
Enough about Endo (Can seriously right essays on it). Weapons.
There are two ways to go, in my opinion. One range, or all range. Now, don't think this means that you shouldn't have anything to cover your butt if something gets close. But don't hamper your intended main-role either trying to cover all bases. But really, when was the last time the Mguns on a missile boat scared you away from staying in that 179and Under LRM free zone? Some MLas's? Right. You just need something that's going to help those helping you scrape the Lights off. OR, you build evenly across all ranges. So in that Catapult A1 (Please don't ever buy an A1), you ONLY have missile options. So, a 'good' A1 is not going to go all 6 hardpoints as LRMs, 4 will be LRMs (2x 15s, 2x 5s, imo), and 2 will be something short range (SSRM would be the most efficient fit, likely)
Now, if they were to ever implement Med. Range Missiles (MRMs), you could build the rig to have a constant feed of max efficiency missile raining down on targets (Wouldn't THAT be fun?)
Fine tune. Since we've been given this awesome drop system where we don't know where our jackass flight crews are going to be dropping us off, you need to make sure your rig can handle the roughest situations. If you're overheating after two shots in the Caldera on Caustic.....you need to rethink your battleplan. (Testing Grounds, ftw). Better yet, if you've built something that can overheat in Frozen City....
Sustained Ballistics vs Boom Ballistics. AC20 weighs less than two Ultra AC5s. So why go heavier and take that chance to jam? Because the UAC5s fire faster, and put out more damage over the course of a fight than the AC20 does. The downside? Other than that they jam? Is that the damage can be spread out. That AC20 is going to knock an arm off first contact, the UAC5 is going to need a steady bead over a couple seconds. So, is your rig going to be relatively 'clumpy' (Atlas), or will it be able to keep that bead (SHD). Are you brawling? or are you attacking at range? Clumpy, brawling Atlas can make really good use of twin UAC5s whereas it might just as well not have ballistics in some matches carrying a AC20.
Pulse Lasers vs Reg Lasers. Same thing applies as above. If your rig is just not quick enough to keep a sustained beam on a target, pulse is a better option. It's hotter, heavier, and shorter range, sure, but if you're not getting even 1pt of damage out of the 'better' laser, who cares?
Missiles. Now this is where it gets funky. One LRM5 might seem a waste, but it's low heat, takes up relatively little space, and can aid your missile boats by eating up AMS ammo. That would also mean don't waste any missile gear on it. So, when is the right time to start placing missile gear on a rig? My rules of thumb here; Never use Narc (it's a tool for teammates to use to help you out). For every 5 missiles over ten, add a piece of missile gear. You go from a 'trollololol' LRM10 up to a 15, use Artemis. If you're rocking a LRM20 (hopefully shot in 'waves') add a Beagle, and if you step up to 'minimum boating salvo' LRM25 (a 15 and 10 or 20 and 5) , add that final piece with TAG. Missiles are a lifestyle, not a hobby, though. To make any real use of them, you're going to be dedicating an awful lot of crit space to them. So, boat or troll, don't try to do both. 30 missiles fired without any assistance might as well be fired into the dirt.
So, that Battlemaster 1G you've got with the LRM20 and no other missile gear to support it?....../headshake.
This has been longwinded enough, and you can talk 'theory of 'mechcrafting' all night (for some), I just hope some of this is helpful to somebody (At least anyone whose eyes are still intact)
edit: Didn't say a thing about engines, in all of that.....this one is quick though. Watch closely to just how much extra speed you get from upgrading an engine. Unless it's getting you an extra heatsink, 3kph extra probably isn't worth however many millions the upgrade is going to run you. You can eyeball about how fast is good enough for you. Drop that engine in on Smurfy's and see what you can fit in. Doesn't even have to be what you want, just get yourself an idea of how much will fit in.
Edited by Mercer Skye, 13 December 2013 - 05:01 PM.