AMP or Preamp

I would start with amps first. 2 large mono blocks and 2 mono block tubes. Once you have your base , go for a preamp that best suits your needs. A cherry on top sort of speak. 

Do a search for the Audiogon subject below: someone just spoke about the Belles integrated the other day. I had Belles pre and amp years ago. It was well ahead of its time and at VERY reasonable cost!
<BELLES 250i INTEGRATED AMPLIFIER>
Bent

An ARC integrated would work nicely in that budget I think.

Replace the Yamaha and Rotel , for a Hegel poweramp, and even pre-amp. No McInt. Also a good option is a tube preamp.: Audio Note, Ear ,..
Also a very good match is GamuT and /or Gato.
Do you want an “American”: best option is Jeff Rowland. All those thinks gives a good sound with your Dac and speakers. For me the best matches. Try them first and  , make a choice.
Enjoy your music!!

You might try contacting Wilson and ask them what amps they use at shows to demo their speakers, where they'd be wanting to make a good impression. Not knowing enough to choose an amp for my Magico A3's,  I contacted a VP there and found out they were demoing these speakers at shows with Luxman 509 amps. So I figured I couldn't go too wrong with a Luxman even though I could only afford the 507 model, one step down. Did the same with the speaker cables.

The Magico company's president had recommended a Hegel integrated amp for the A3's in articles I'd read, which I'd also seriously considered. But Hegels being manufactured in China, where quality control is such an endemic issue, was too big a chance to take on a big purchase. 

Mike