AMP or Preamp

Good to hear that you did whats absolutely right. Started with the speakers. I would be careful spending a lot of pre/amps to begin with. Buy some cheap and good class D like XTZ Egde. Then you have power enough. See how you like it. Don’t need a pre to the Vault. The next is your room. Adding a professional room correction unit would make wonders to your overall sound. And will also educate you in sound/listening. No speaker presents a correct frequency curve in a normal listening room. 

I second asking Johnny at Audioconnection. He knows just about everything out there, even if he doesn't sell it. And, he won't denigrate it, either. He'll give you an honest answer even if he won't make a dime.
One of the best...
Bob

It seems nobody has anything negative to say about PS Audio, Audio Research and Pass Labs could be a good place to start.  

All three would be good choices.  Wilsons are extremely revealing of upstream components, so I would try several if possible.  

I really like the way my Wilsons sound using Atma-Sphere MA-1 mono blocks which I found used, in your price range. I have also heard Wilsons powered by ARC Ref 150 and that also was a great match.

I do not own Sashas so if you do decide to look at used Atma-Sphere amps I would contact Ralph directly ((651) 690-2246) to get his opinion concerning the possible impedance issue. He will have a solution if there needs to be one.

I also agree with an earlier poster that said almarg and atmasphere are very good resources on these boards.