A very very good class A/B (with bias set to get low moderate power as A with single and balanced inputs would be very nice indeed. Price in the under $2K range.

Agreed. Somthing like the old Adcom 555II. I would use that for the mains and the 5 channel for the rest of the system. That way when I listen to 2 channel I get the upmost quality and only have to power up tat amp.