The $50 ATI 3450 video card is probably the only thing you will need! Well you will have to purchase anyDVDHD and PowerDVD as well.
that's what I though on the GFX card. I'm in need of an upgrade on that badly anyways, probably grab the 8800gts. Luckily I already have PowerDVD and AnyDVDHD (I picked that up earlier when slysoft had a good sale).