"I highly recommend getting a network TV Tuner. Namely one from HDHomeRun. They're several different models and offer ethernet ports so that effectively you can share the tuner with other computers. I do this at home currently, but I don't do it over wireless (CAT6).
Having a network tuner is much more valuable than putting in a tuner into an actual PC. When you have a tuner in the PC itself, no one can really use the tuner but whoever is using that PC. With network tuners, if demand grows for more TV streams, you just simply buy another tuner and set it up on the network. No hassle or fuss. HDHomeRun is simply awesome. It's also compatible with MediaCenter and MythTV."