Might be helpful if you tell us what sort of T.V you wish to run i.e Sky, Free Satelite, Free Terrestrial HD, Analouge etc as choosing one of the easier T.V Capture cards will make your life a lot easier.
I am running an ASUS Motherboard in my core with a new I7 processor and it runs sweet! The only problems I had with setup were/are related to one of my T.V cards which is a hybrid and initially a problem with the AV wizard which turned out to be to do with my network settings.
I will by trying some Thin Clients and also a small nano motherboard with integrated touchscreen for use as Media Directors in the coming weeks if you are not in a hurry. The system is great and well worth the effort!