i have a cheap unknown brand philips saa7130 card(most saa 7130-34 work on linux perfectly), tvtime sees all the ports and i can connect my minidv camera to it without a problem but never tried to capture(my tv card has lots of noise) so can't recommend about the whole process(supposedly all you need is xaw-tv, no idea about that)
stay away from nvidia and ati tv cards, none of then has any form of support on linux, at all(ati older models might work, older as before all in wonder models-2004)
haupagge 150(no idea if 300) and the cards using saa7130-34 are known to work for tv viewing, capture is different but should be easy to do