Should I do this now or wait...

Second Blindjim,good luck

The advantages to biamping http://sound.westhost.com/bi-amp.htm

There are advatages IF done right, especially if you use tubes for the top and SS for the bottom. If it is worth the effort, is another question altogether. If I were to use and SS for the bottom, I would not spend as much money as a Pass Amp, I think you could get alot of great SS bass from a much cheaper amp (for bass only).

I think you'd be a little nuts to put two x250s in a room. I had one and it threw off a ton of heat almost like a tube amp. My wife said "something's wrong with your new amp, it's burning up or something." It was literally warming up an 8' area around itself. Yes, it sounded good but not really practical IMO.

Wireless200, I am running 2 Nakamichi PA7s right now full time, each drawing about 260watts idle in passive biamp mode, it sounds very decent, contrary to what Shannere (Thanks)weblink article mentioned as having little benefit. The overall sound quality just seems punchier, cleaner and yes, the system plays much louder as well. I got a huge room (typical open floor plan 50Wx40Dx20H).
One unexplained oddity w/ the Naks are that using the Y splitter for the inputs, they cause loud turn-on pops, forcing me to leave them on all the time, which is quite wasteful which I am trying to resolve maybe w/ different amps...I totally understand the many benefits of active crossover (tried it w/ homemade subs and Paradigm X30 crossover for a few years) but generally speaking, some clarity and intimacy was lost and balancing was difficult, realizing how complex the passive crossover setup in the N802 is I do not want to mess with.