Take a look at one of NAD models. Very good for the price, and you can use them as a preamp should a vacuum tube bug bit you 
Boris's amps are *very* good as well. I didn't get to hear it side by side with the other amp, but if 8-15 watts is enough and it sounds like it should be given your speakers, then these are great choices.
Hey!
Yes, Audio Vista amps sound pretty good I agreed. I've heard the little PSE 5 watters that Boris bought over to my Mini-Rave. Pretty darn good for the price.

His 15 watt PP EL84 cost more than your budget but I've heard it during NY Rave at topround/Mike's place driving the Green Mountain's Europa. It was very nice.
If your speaker is a
ture 96dB with simple xover and relatively flat impedance than even 5-8 watts SET should be able to drive them nicely in small to medium size room.

And 15 watts would be great with more heard room.

Anyway, if you are handy with soldering iron than you might want to hunt down old console amp like Maxnavox PP (EL84 or 6V6) amp.... but I think you will need pre for these

Or if you can an old Scott integ-amp. They do come up on eBay from time to time.
Take care,
Buddy
