If you're prepared to be patient & stretch just a little, i'd vote for a 2nd hand McCormack DNA-500. Good examples can be found found circa $3k. The DNA-500 sounds tube-like and is musical sounding, and will also have enough power to drive pretty much any speaker you might throw at it in future. They don't last long when they come up on the 'Gon & there is a good reason for that; they are a really nicely designed & built amp & a flat out bargain for their asking price.
