Pre/power or Int Amp for Wilson Sophias?

Yep,own the speakers. This is just my opinion: I think you should set your sites a little higher and go with separates. I have a high end set of tube monos (CJ8xs) and a SS stereo amp (Belles 150a reference) Sure I can hear the dif. in the amp (s) being used.--That would be the case on any great speakers-- I also use the Placette Passive, cheap but great. My pre is on a stand close to the amp so 1 mt.of cable makes the connection---Just because this speaker sounds good on most any amp doesn't mean it shouldn't be better fed. A great front end inc. "all=the-wires"and a great conditioner helps a bunch,too. Neither of my amps R bright. To me bright comes from a cheap front end,cheap cabling and cheap amp/pre.--Hardly any of the good stuff is "bright".

Looking at your preferences, I would take a look at these;

Ayre K-5xe preamplifier
Ayre V-5xe power amplifier

Great all around, musical, and as you requested, not bright.

If you can skip the SS, you might consider Balanced Audio. You could go SS on the amp, tube pre. The tube pre's, especially used the 6h30 tube are about as care free as ss. Tube change every 3-5 years. You'd really never know there were tubes in there unless you peek.

Maybe a vk31SE and a vk250, vk500, vk200 amp.

BAT's integated is a good choice to for 1/2 your budget.

CJ is coming out with a new 150 watt control amp this fall. It is based on the Premier 350 and should prove exactly what you need. I would take that over most other options.