Looking for reccos on a surround amp and possible second sub

Alright, I'm looking to create a y2k b&w system. I've got signal coming from computer to Geshelli j3 DAC, over to anthem avm70, and out to an odyssey stratos extreme to 804 nautilus. Piggybacked is the REL t9i.

That's the 2 or 2.1 but I'm looking for another setup for film and gaming.

I don't have an amp yet but I do have htm2, 805 nautilus and two pairs of 7nt signature in wall (that's I've put into 1.5 cu/ft boxes with all the fancy dampening. I might use the 7nt as heights eventually but it's a pickle in the current room.

I have my eye on a b&k reference 7250 series 2 ($550) for the surround system but the 804 will stay on the Odyssey.

There's also a Sunfire Grand TGA 7201 ($1200) that seems like it might be a good choice.

The B&W, as you may well know, tends to be a touch bright so the Rotel 980 BX that I have probably aren't going to help.

I'd love to input on a 5 to 7 channel amp and would it be reasonable to add another sub for impact? If so, should it be another t9i or a different but complementary option?

Budget:

I'd love to keep the five channel $800 -$1k or below if I can and the same for a sub... But it's possible I'm being ridiculous.

The goal here is just the most cost-effective end game system I can possibly purchase. I don't want to do all that audiophile stuff.

Location:

I'm near Boston.