Well Gordon, I use Magnepan 3.6's powered by a NAD 218THX amp, MMGC center channel, and 10.1's for surround sound duty, and an SVS PB Ultra 2 for a subwoofer. My room is 26Lx12.5.w with a peaked ceiling from 7'10 to 13'. My room is more on the live side, with GIK corner traps and bass traps, plus some GIK and ATS QRD diffusor's.
I think your system should sound fantastic, Maggies will crank some sound if you feed them enough power. I have my sub crossed over at 40hz I also MYE Stands on the 3.6's. I have heard they can give you some lower bass, mine go down to 37hz. If more mid bass is needed their is always Magnepan's DWM woofer, if I go that route I am going to have to change my room around, might be interesting as they say you can reach Tympani's leve of quality bass with two of those.