I have not heard a set of Wilsons like you have before - but I’ve heard from associates on other forums that the’re awfully nice / revealing.
It sounds like you already have some pretty decent sources, and the Power Amp that you have could be better, but it’s no slouch either.
If I were being "semi-practical" - looking for high quality, but VALUE = I would be looking at some of the BHK Signature products from PS Audio (Hybrid Tube / Solid State - taking advantage of the properties of both in a "synergistic" combination) Maybe start with the Pre and upgrade to a nice pre-owned set of monoblocks to replace the Rotel Amp later.
Another two decent brands to try for Pre-Amps (Line-Stage) would be Audio Research and SimAudio Moon -
I have heard a local high-end dealer’s demo system - with Vandersteen Model 7 speakers being driven via Audio Research Reference tube components and other goodies. (That was a system in excess of $100,000 retail) The imaging and black levels were almost "spooky" - but for that kind of moolah, they SHOULD be!
The solid middle-of-the-road Audio Research stuff or older, refurbed Reference stuff might be attainable
But with a system like yours and the amount of your budget - I would certainly:
-Audition a few units, to see what sounds best with the rest of your Sys
-Only buy from places with a good Return Policy, so that if you don’t like the way it sounds, you can return it for a (at least nearly) full refund.
-Find a forum with other Wilson Speaker owners, and see what has worked for THEM.
If you want to keep the system "sleek" = minimize the number of boxes to be interconnected, I have it from a reliable source that I trust (a different local HiFi dealer who carries a wide range of price options) that the Hegel integrateds are awfully nice.
