Spendor s3/5 amp

I think I've narrowed my search for a nice monitor that will do well near a back wall to the Spendor s3/5.

What integrated would be a nice match for the Spendors? I'm looking to buy used, and the budget is around $600, but suggestions for cheaper options are always appreciated! :)
used creek integrated amplifier would fall into your budget and work with these speakers...sophia el34 used would be close and have plenty of good sounding tube power

there are a lot out there
is the conventional wisdom for a good match with spendors, solid state or tubes?

i've got a lead on an audio refinement complete, as well as a creek a50i, a rega brio, or an nad C320BEE...

or could do one of the budget tube offerings, from jolida, ming da, dared, etc...