OK that PC would handle all your needs but I'd add a GPU in the mix too for the GPU acceleration. For the other tv's I'd get a WD live box. they can be had for like 100 bucks and play media on their own if you don't want to store everything on the network.
Someone may can come in here and list out some better hardware for the same price or a little more. I don't keep up on hardware much.
Take a look at some PC's on there some nice hardware for cheap prices. I got my father in law a system to build him off there 2 weeks ago for a good price.
A system like this would cover all your needs I'd think. If I'm wrong someone please say something. No idea of the build quality of the hardware but hardware wise this would cover your needs. Some of the reviews on there say the case sucks.