What amp to drive Magnepan MG12QR's

I asked a similar question a few days ago including 3 specific amplifiers I was considering. I am looking for opinions for other amplifiers to drive a pair of Magnepan MG12QR's. I want to spend less than $1,000. Please share your opinions or your thoughts.

Preamp:
VanAlstine Super PAS 3si (VanAlstine design not Dynaco)
I'd like something that will work well with this preamp.

Below is the rest of the system. Right now the only thing I want to improve is the bass. I want to tighten it and give the system a little more slam. My room is 14'x 13' with a 14' ceiling.

Oppo 980 with Scott Nixon DAC
Systemdek IV (not IIX) with Rega RB600 and ATOC9ML II
Rotel phono stage and DB Systems phono stage
Modified Dynaco ST 70 w Sound Valves input board and
many updates.