Best power amp for under 1K

Counterpoint SA or NPS series if you like a tube front end with ss output. For all ss, I would start with McCormack DNA series.

Monarchy SE-100 or McCormack DNA-1, after owning botjh I can't pick a clear winner. They are both very good amps for the money. The Monarchy is a little brighter sounding while the McCormack has a little mist to it. Either way you can't loose for the money.

as well as Threshold amps.

http://www.vintageamprepair.net/

Jon Soderberg. Truly the expert/Guru. Famous for his upgrade/modifications as well as preventative maintenance. Soderberg used to be with Threshold and Threshold owned Forte'.

So, you're really covered concerning support for Forte'&Threshold.

A used McCormack DNA125 wouldn't be a bad choice.

I recently purchased a used Balanced Audio Technologies (BAT) VK-200 for right around $1,000. I love it.