If PGI fixes the center torso with the Orion STD engines could be used for increased survivability aka zombie. Nothing fancy. Just 4 arm mounted medium lasers to melt armor and a class 10 autocannon to punch holes into the internals. With 45 autocanon shells it should be barking whenever targets are in range. Follow up with a pair of torso mounted SRM-6 packs to exploit the weak areas. AMS provides missile defense and a STD 300 engine moves things along. Heat is a generous 36% for sustained combat.
~S~ Cujo! Good point about the CT. But if you're going to run Orions, and you aren't going to pack and AC20 (or 2 LBX AC10's), consider a XL engine. My Orions haven't died yet from a right or left torso blow out. Consider then, this build, a fast brawler. It features the same load out (but 3 tons of ammo for the AC and SRMs) and a max XL engine. This thing can close fast. If AMS ain't your thing, you can swap it for BAP and get into 150m of those nasty DDC's and nullify their ECM.