Bryston 9B-ST or Pass Labs X5

I was wondering what sort of thoughts people had on using a Bryston 9B-ST or a Pass Labs X5 in a home theater set-up with the following equipment:

Processor -- Sunfire Theater Grand II
DVD -- Sony S7700 (soon to be upgraded)
Front Speakers -- Nautilus 805s w/ matching center
Rear Speakers -- Natulis SCM1 (flat, wall mounted version of the 805)
Interconnects -- Nordost Red Dawn (Balanced)
Speaker cable -- MIT T2 Bi-Wire (front)
Nordost Super Flatline Mk. 2 bi-wire (rear).

Any thoughts would be appreciated. Originally, I thought about using a seperate 2 channel for the front speakers and a three channel for the rest, but have ruled that out due to space (wife) considerations.