Not much you can do with this mech. tried 4 MRM 30's with 4ERMED and it was too hot. 4xMRM 10's was too little damage but this build is pretty decent. you can chain fire your ERMEDS on 1 and chainfire or fire all of your MRM20's without much heat build up.
29% heat efficiency is damn hot. STD325 version, 2xMRM30 (no ghost heat), way more cooling, less ammo (1200 MRM unskilled... More than enough IMHO, I don't think you will often last more than 20 alpha strikes, 24 with skills) LE325, 4 ton ammo, more armor stripped TC1 EDIT: or simply drop the LE345 for a LE325 and fit more DHS... 33% should be barely manageable
also possible. ghost heat on dual 40s is negligible. Dual 30 with a few ML is the same firepower as my Marauder but it weighs more and moves slower.