Okay, so first question was; Which modules are best.
So, under the assumption that you're going to acquire these, and don't have them already;
Target Decay
Sensor Range
Radar Derp (For LRM dueling) or Target Info Gathering (Because you pack lighter direct fire, you REALLY need to know where to shoot)
Missile Cooldowns
Secondary weapon Range/CD boosts
Now, I'd seriously reconsider the idea of straight up boating LRMS (Understand that Missiles as a primary system is NOT boating, and a lot of people get confused on that). So, I'm going to assume that you want to use missiles as a PRIMARY weapon and not a BOATED weapon.
Some builds;
LRM-Master (BLR-1S) This is a more forgiving LRM build, and my suggested 'learner comp.' This is the 'boat' you use when first starting to learn the maps, how to properly use cover, and how to stay close enough to your group to be more than 'that guy' hanging out a click back lobbing ineffective salvos over everyone's head. While the best missile users can keep in line of sight of the enemy to properly use Artemis, there are times where you need to hunker down behind a nice cozy rock and just throw supporting fire into the enemy line.
Weapon Grouping; One grouping for arm launchers, one grouping for chest launchers, and one grouping for all launchers on chain fire. When you get into a situation where you can just go ham on lobbing missiles, you can fire the first two groups with a one second pause, and just hold down the 'all group' button and avoid ghost heat for the most part. One grouping for the medium lasers should be fine (That Pulse is in there to make up for lack of a fourth because of Tag). And obviously, you need the sixth grouping for the Tag.
Punisher (BLR-1S) Now that you've figured out how to properly use cover, we streamline the tube count (From 40 to 30), and provide a better brawl package. This is probably where you swap from the Target Info Gathering module into the Radar Derp, now that you can put a bit more punch into your close firing weapon systems. Now you've come to the point where you can get out of cover, throw a well streamed salvo into an enemy, and fade away. Pulse lasers and a pair of streaks seriously punish any light foolish enough to think that you're just a regular ol' missile boating Assault Noob.
Weapon Grouping; One for LA, one for RA, one for Tag, One for Lasers on chain, One for all lasers, one for Streaks.
Slingshot (CPLT - C1) Now that you've gotten used to how to 'boat' with the forgiving armor of an assault, I now suggest you step down into 'mechs that are more properly suited to being missile 'mechs. The A1 is very popular Catapult, but I much prefer the simplicity and more rounded weapon package of the C1. It also has the advantage that it's missile package is very similar to the 'Punisher' BLR build you just stepped away from. LRM 15s are easily the best IS launcher, and with artemis, they are quite deadly. The Catapult, near as I can tell, has some of the best firing arcs, so you can make much better use of cover when needed, and with Jump Jets, you can get into much better 'sniper' positions on some maps that the BLR just is not privy to. Granted, 9 tons of ammo might be a bit much for just 2 launchers, but I've honestly never had much problem burning through all but a ton and some change, and have had on more than one occasion only one or two salvos left in the tubes at the end of a match. Can't honestly remember the last time I went dry, but if you're finding more than a couple tons of ammo left at the end of matches, you can always drop 2-3 tons of ammo, and bump the MLas's up to Pulses, I wouldn't necessarily bump the engine up, as ~70kph is about the perfect speed for a missile 'mech, since you're likely not outrunning lights/mediums anyway, and a little more speed isn't really getting you away from other Heavies or Assaults fast enough to make much difference.
Spartan (GRF-1N) Now, you REALLY want to show off your missile prowess. One launcher, and enough close range weaponry to rip open the internals of sections you've stripped the armor off with your LRMs. You can always drop the engine rating down, and put some more ammo or 'oomph' into the build, but this thing seriously wrecks face as is. Precise missile placements from out of nowhere, and fading back into cover, Medium Lasers and a pair of streaks for crippling/killing lights and eating up internal structure, and you're fast enough to move from lobbing LRMs to spotting for LRMs.
No lights? My honest opinion is that while there are quite a few fun builds you can do for lights (in the IS anyway) that use LRMs as a primary system, it's really just trolling your team to do so. Now, you can easily make lights that take advantage of LRMs as a secondary system, which is fine, but I just don't think they're capable of using them as a primary system (Shy of the Oxide, maybe, but it's honestly better as a Streak or SRM boat)
Edited by Mercer Skye, 07 April 2015 - 08:01 AM.