Recommend small, low power but low noise monoblocks

I've long thought I'd like to go to try build an active crossover system with dedicated monoblock amps driving high efficiency speakers. (2 way system only)

What amps would you suggest?

I listen to chamber music, acoustic and some jazz at low to moderate volume levels.

This would be a computer based source.

I'm willing to entertain the possibility of a DIY route if that works best. I have some rudimentary DIY skills -- I managed a successful assembly of a Bottlehead Preamp.

I really want neutral sound with a very low noise floor. I think I prefer the no fuss of solid state but would not rule out tubes.

Any thoughts you might have would be appreciated.

First Watt DIY sounds like a perfect fit for you. I've heard many all punching way above their weight class and without doping ;-).
I have a Forte' system ( Nelson Pass Design ) model 7 mono blocks / 75watts; pure class A and matching model 40 preamp w/ Phonostage
I'd look at a pair of NuPrime STA-9's. Lots of flexibility down the road. 

Or for less money go for a pair of Parasound ZAmps. I've used them in both stereo and bridged mono and they are excellent for the money. Truly standouts in the Z line. 

- Woody