Preamp strategy advice for 2 ch. HT

My current system includes the following:

Denon AVR3300
Parasound CD/P1000
NHT 2.5i
NHT 1.5
NHT AC1
Bryston 4B-ST (for the 2.5i)
Sony DVD

My objective now is to get a pair of NHT 2.9 (move the 2.5i to the rear and lose the 1.5's), get a new preamp, and then new amplifiers (Bryston), thereby losing the Denon. I would like to do this piece by piece. My question: should I get a 2 channel preamp with a HT passthrough (Adcom GFP750, Bryston BP-25, or the like) now, and then lose the Denon later, or should I look into getting the Bryston SP-1 Preamp/Processor, which includes the BP-25, but also serves the HT role. From what I understand, Bryston intends on supporting the future formats once new ones become mainstream. I gues my question is should I go separate 2 ch. pre, or look into the dual role unit?

Thanks

Lee

Any thoughts?