You should consider the Unico or Unico SE. The former is generally available for less than $1000 used on Audiogon. I had one driving my Spendor S3/5se to great effect using Cardas neutral reference cabling. This combo was one of the more musical systems I ever enjoyed at a modest price point. Interestingly, the same Unico was later paired to my Harbeth M30's - again a very nice combo with a similar sonic signature.
Regarding power requirements, the Unico (rated at 80w/channel) easily drove the Spendors (I rarely had to move the volume dial too far to fill my modestly sized living room). Finally, I would not consider the S3/5se's to be particularly power hungry nor do i think they need high powered SS amplification to drive them.
Just my observations.
good luck!