wayne, I've done this before. I have an s-video output and it just plum sucks. It should be a clear picture too because I have a high quality tv. I was hugely disappointed. I wouldn't go making plans around anything like that.
I just gave it a whirl on my current computer, 6600gt hooked up via S-Video to the TV and i was impressed. All we have is a 59cm CRT TV, nothing compared to some of those 1080p Plasma and LCD TV's. On our TV it looked nice, even Divx TV episodes looked good.
http://www.msy.com.au/Parts/msy.htm
that place has pretty cheap prices for video cards. AU$53 for an FX-5200 (Asus or Leadtek) or AU$209 for a 6600 GT (leadtek)
or there's also http://www.cpl.net.au/
they have a pretty wide range of video cards, prices are descent too