Wow LBT, sounds like you've considered most of the same stuff in a lot of detail. My biggest issue is going to be interfacing to the SKY isn't it? I don't really want to pay them EVEN more money to get multi room, I'd rather use terrestrial with Sky purely for the premium stuff.

Client/server would be fine by me, I've seriously considered a Win Terminal Server environment before but that's the only thin client (apart from slim devices) I've ever used.