Sentryl,
First, you're going to need a PC connected to the TV. There's really no good way to connect the TV from 70 feet (bad quality signal). I've done just what you want to do. I have 2 PCs, one is a server, and the other is a client. The server is connected to the TV. The server iss maxed out, with a GeForce 4 Ti4200 videoa card, 6ch Dolby Digital Soundcard, PVR (personal video recorder) card, P4 2.2 GHz, 1 Meg RAM, etc. The client can be a dumbed down machine with the basics. You have to make sure the video card for the PC connected to the TV has video out (preferrably, in my opinion, S-Video out). You'll run, in the S-Video case, an S-Video cable from the Video Card to the TV. Next, you'll have to network the 2 PCs (either wired or wireless, your choice, though wireless is more expensive). Then, on the client machine, install a program called "Radmin", which you can find by doing a search on Google. I think it is $19 or $29. Install Radmin on both PCs. Then, from the client PC, you'll be able to view the Server PC and control what it does (start programs, download music, etc.), and since the server is connected to the TV, whatever you do from the client machine will appear on the TV.
Hope that helps. Email if you have more questions.