The PeachTree GAN400 is rather good for the $1000ish used price. I had it 2 times on my Magnepan LRS+ until I finally found the Sanders Magtech amp which is better for much more money.
I used to own the older PEachTree NOVA 150 and found out via some testing that the amp section was good, and the preamp section was lacking. Not sure if the new preamps from PeachTree are better.
Those Hegel integrates mention above are also pretty good.