Amp for Nautilus 801

I currently own the B&W 801's and am driving them with Bryston 7Bsst monoblock amps and used along with a CAT Ultimate MKII pre. The 801's are a demanding speaker and can handle alot of power. I can only speak for the Bryston's and can say that they effortlessly feed these speakers. They are rock solid on the bottom end, Mids are precise and Hi's are detailed and not overwhelming. They are quiet running and when put to the test, these 600w amps can produce some heat. The warranty from Bryston is one of the best and carries over if sold second hand. I believe for the money that it will be hard to beat their performance. Also a large listening room is preferred with these speakers to appreciate what they are capable of producing. For those tube amp lovers I have heard (by word of mouth only) that the Bryston's lean towards a tube sound. If you have a chance of auditioning these 4 amps that you've mentioned by all means line it up, for it will be well worth it to you and other Audiogon members. Take your time in choosing and above all HAVE FUN doing it.