Advice for Neophyte Assembling a System

I own the Sophias and use, as a back up, a Pass XA30.5 rated at 30 watts with similar room restraints as yours and it works marvelously. With that said the Sophias look to be a bit more efficient than the Sabrinas so I would hesitate using 30 watts and since you are system building from the ground up go with a more powerful amp. The Sabrinas are a great speaker and should work equally well with tube or solid state amps. My preference on power and pre would be separated with no hesitation for all the obvious reasons. Happy listening and if you do purchase the Sabrinas let us know how you like them after they are settled in or what you choose instead of them and why.

Thanks very much for your thoughts. Greatly appreciated. Wondering which amp you might suggest would pair well with the Sabrinas? 

There are a load of great amps out there, tube and solid state, for the last year and a half I have been using a pair of Quicksilver M120s that I got a very good deal on brand new, never unboxed from a guy here on Agon and planned to use them while my VTL 125 monos which were 20 years old were being rebuilt by VTL, liked the Quicksilvers as much so just sold the failing VTLs to a guy that was going to do the work himself and never looked back. You seem to be in the solid state camp and am sure you will get some great recommendations on those as well. $40,000.00 is a very attractive budget and is about what I have in my system after all is said and done, which I am except for funds needed to replace any failing components when the time cones. FWIW I have seen a few pairs of the Sabrinas come up here for less than $10,000.00, either way you should be able to get one hell of a system for your investment.

If you like Sabrina's then you should like Vandersteen.
Unlike Wilson, Vandersteen's are time and phase aligned and are very easy to drive.
The Pass amp mentioned offers a lot more power than conventional amps-Mr. Pass usually underrates them.
Wilson's are known to be difficult to drive speakers (though newer models seem to be less so). 
I just looked at the specs and Wilson recommends 50 wpc. which seems reasonable. I think any speaker you get will need at least that amount.
The more power available, the more headroom for transients and little things that give music its' 'sparkle'.

From what you posted, I would also look into room treatment.
Glass is one of the worst things for music-highly reflective.

My 2 cents...
Look at lots of different speakers and find the characteristics you like.
Then narrow it down and make a decision.
After that, deciding on amps, preamps and sources will fall into place.

Lastly, where are you located? Any dealers near you?
Bob

The first, and by far the most important advice I can give is to go out and listen. A lot. To as much as you can. The budget you've got, anything less than stellar blow your mind results ought to be considered total failure. In fact, scratch that. Not just yours. Everyone's. Seriously.

Because quite honestly the results people get depend a whole lot less on budget than time invested listening, auditioning, and learning. There's hardly even any correlation between money spent and results. There's a system right here in Seattle, $1.3M worth of absolute train wreck dreck, stands testament to the futility of throwing money at the problem.

The second most important, which if you really take the first to heart you will discover on your own, but its worth making explicit: you absolutely must budget significant funds for tweaks. Power cords, speaker cables, interconnects, power line conditioner, fuses, room and component treatments like HFT, ECT, and so on. By significant I mean it wouldn't be excessive at all for half the budget to go into these.

Listen, learn, audition. Repeat. Patience is a virtue. The flashy big ticket components everyone already has dangling in front of you, you have no way of knowing now what a total distraction it is. And they are.

There's some general rules. You'll get better results with records than CDs, with tubes than transistors, and with integrateds than separates. You'll get way better results with two speakers and a Swarm than the traditional sub approach. But really its that first rule. Go and listen.