Thanks, for the many suggestions. If it's helpful, perhaps I can share the rest of the equipment which is a bit of old and new.
Preamp: Marantz AV705
Amp: Marantz MM7055 (powers rear & side surrounds plus center)
Amp: two KAS2 (one is now broken, circuit board is fried so it probably can't be repaired)
Speakers:
Fronts, Apogee Diva Ribbons
Center: Apogee
Sides: Niles in ceiling
Rears: Heybrook HB.5
Sub: Velodyne ULD 15
Projector: JVC DLAX93D
plus the usual other stuff, bluray, svhs, turntable, power conditioner, etc...
So it sounds like I should look into Icepower and Sanders or perhaps a new Krell (which seem to be very pricy). My installer is recommending the McIntosh MC302 or a Mark Levinson N532H - but at about $6,000 that's more than I wanted to spend.
In the meantime, I had a Rotel RB-850 lying around that was unused so I hooked that up to the Apogee Divas. After rebalancing with Audyssey, it sounds 'ok' to me but to be honest, I'm not sure if I know what to listen for. I'm also a bit afraid to turn it up very loud but we just watched a movie at a normal volume and nothing melted or went up in flames :) Any thoughts on why just using the RB850 is a bad/good idea? Thanks again.
Best,
Scott