I have similar requirements to you.
I'm after something I can stick in a HTPC to make a PVR box.
Basically, as I see it (and I'm going down the shuttle route which complicates things further) there are many different options:
1. ATI AIW (AGP or PCI depending on model)
2. ATI G/Card (TV out) and a Hauppauge WinTV-PVR PCI
3. ATI G/Card (TV out) and some other TV Card
4. ATI G/Card and some kind of USB2 TV Box (don't think these exist yet, but they must be on their way...)
In an ideal world, I'd like to have the choice of using 3rd party software. That pretty much rules out the ATI AIW because nobody knows how to talk to it apart from ATI it seems.
Hauppauge (depending on the model) might work with linux (for example), but I'm not entirely sure of that yet. This website
seems to imply that the WinTV-PVR x50's don't work with linux yet.
Alternatively, you could get one of the brooktree/connexant TV cards (generally these are quite cheap) and then linux isn't a problem... but I don't know if the picture quality (PQ) of these is as good as the AIW or the Hauppauge
Can anybody suggest any other options?