first off, a card with open gl support, go get the old tnt riva, that runs the q3 engine no prob.
$50 or less for a card, nothing out there worth investing in now, save up for a better one, as the $50 cards may not run everything and have already outlived their lives.
more then 80 gigs? well, i own about 60 games all the way form wolf 3d to KoTOR, witho about 15-20 over a gig and a half in themselves, add that to microsoft office and visual studio, countless web sites and graphics for them, a lot of music (since my pc is my cd player, i put all my cds on there), and a partial completed game engine project, 80 is no where near enough, and since i only have 60, i only have about 15 games in rite now, and most of my data and graphics i have on cd-rw instead of the HD, lol