Personally Neuro, I'd simplify and just run Active Directory, and maybe WDS to deploy backup .wim's. That way for each client, you have a specific OS setup, and any hardware/software changes you can perform offline and keep this stream line. Those $100 SFF's should easily handle flash and video streaming without depending on the server. To go your route, you say you have a powerful pc at home, but with everything you want to run, you'd soon learn that pc's are not servers
Right now, RemoteFX is only supporting FireGL or Quadro (at least the last time I checked), with enough memory for each client to run video encoding for streaming (depending on what they watch of course) you're looking at 275 MB of v-mem from the server gpu for 4 thin clients running just on the desktop, no streaming. Something to take into consideration.
Sorry for going on and on...this is what I do for a livin' lol.