I've used Hauppauge in every media pc build I've done - four & counting so far, through XP, Vista & Windows sorry, er 7 and I've been very happy with the performance of each one.
Having said that, I've always used the tv through media centre as opposed to the Hauppauge software, which is awful. The main issue you will have though is the aerial - if you intend to use one of the little portable aerials you can buy to plug in to the other side of a tv card, don't get your hopes up for anything like a decent picture or even any at all.