Sounds like you'll want to convert over to an AR-10 pattern buffer system. Parts you'll need: -VLTOR A5 or BCM Intermediate receiver extension -H3 AR-15 buffer -Armalite AR-10 spring (part #EA1095) You can reuse your castle nut and end plate. That should smooth out and tame your recoil some. For a muzzle brake, a two or three port one should do well. JP, Lantac, Precision Armament, and others make good ones (and they're not suuuper different from each other). Stocks are too subjective to make a single recommendation, but lots of people like the Magpul STR, ACS, ACS-L, and MOE SL. There's also the B5/LMT SOPMOD and B5 Bravo.