demo or nice used pre/pro & amp

Ok are you guys ready for this one I,m sure it been submitted for review before. I,m in the market for a pre-amp processor (5.1, dts and dual zone capable) and a new 5 channel amp. I use my system 75% for H.T. & 25% for music. I have a new Mitsubish 55in. wide screen with Paradigm Ref. 40 speakers and paradigm ceiling speakers in the rear. I'm really torn between the B&k ref30, Parasound 2500u, and possibly the Sunfire TG11. Question #1 Which can perform both good home theater duties and is capable of running my outdoor Nile speakers? Question #2 Which of these toys can be had at a fair price in the used or demo market? Question #3 is it better to try for a demo or nice used unit.

My amp questions are should I go for a Parasound 1205, B&K AV-5000 or Adcom GFA7500? Oh! and by the way My budget is $3,000 for preamp & amp. I know I'm asking alot.