OP- I'd avoid the medium pulse lasers. Their range of 180 is just too short to use, they weight twice as much, and generate more heat than a medium laser. Their only positive characteristic is that the beam lasts .4s shorter, which doesn't make up for all those downsides.
5 tons of ammo for one gun is probably too much- try starting with 3, and if you run out, add more. A good general rule is 2 tons per gun, though. On that note, don't bother with CASE, just put a ton in the head and the rest in the legs. Those locations rarely get hit, and ammo only has a 10% chance to explode anyway.
You're much better off with an AC10 than an LB10. The LB10 spreads out damage even when at close range, which is a bad thing, and it that spread also means that at distances past 100m or so you're probably going to start missing pellets; at its max range you will be lucky to hit for 1-2 damage a shot. The AC10 lets you put damage where you want it more reliably and at longer ranges; it's very worth the extra ton and crit slot.
You'll be pretty undertonned and undergunned if you just make the changes I suggest with nothing else though; you could either upgrade to an ac20 or swap out the medium lasers for a pair of large lasers. Either of those two builds would be pretty solid, especially if you are willing to trade a little armor for an SRM6 on the ac20 build; in general, it's good to have a range where your weapons work well with one another, and the large laser + ac10 combo or mlas + ac20 combo are both hard to find fault with. Personally, if you want to brawl, I'd go with something like
this.
Oh, and unless you find yourself getting hit by missiles a LOT, the AMS probably isn't worth it. In general, it's better to just play smart and avoid getting hit at all; the AMS won't make a dent in a cloud of 60+ missiles, and anything less means it's probably just a single LRM15 or smaller, which isn't worth devoting 2.5 tons to.
Edited by aniviron, 02 November 2013 - 02:29 PM.