If you want to just burn an entire program and not have to deal with editing, then just buy a set top box and hook it up using s-video. Considering how cheap DVD media has become, you may not need/want to remove commericals.
I have a VAIO Media Center 2004 PC, P4, 2.8ghz, 2GB RAM, 500GM HDD space. I use this to record tv shows (in DVR-MS format) and then use either Sony's built in "Click-to-DVD" app to edit out commercials and burn to DVD, but it is verrrrrrrry slow. Case in point, i am right now burning a part 1 of Battlestar Galactica (90 minutes). I edited out the commericials and started the burning/encoding at 7am est this morning and as of right now (6 hrs later) it's not done yet. On the other hand, my buggy Easy Media Creator 7 recently added support for DVR-MS files and would have been done by now, but it's buggy as hell and would have probably locked up.
I guess what i am saying is get a set top DVD recorder as it has to be a lot less of a hassle