I'll be the contrarian here and say that while it would be great to have that multi-room capability, it sounds like a pain in the ass to me to listen to records from a room that doesn't house the turntable. Hell, there are plenty of complaints about having to get up to change a 45RPM record more often than a 33, and that's without having to go to another room to do it! Since you already are planning for two sets of speakers, I'm in favor of a complete system in your listening area. I wouldn't think both systems would have to be of equal quality, so whatever criteria you would use for selecting speakers for each room (in terms of desirable qualities given likely use), apply the same to an amp and turntable.
EDIT: If you go the one-turtable route, I'd recommend an automatic table!