I don't see why you don't get a netbook and a high performance desktop; it'll cost you less than a high performance laptop these days...
Anyway, with respect to the Nvidia cards, anything GTX250 or higher should be fine. The other stuff is OEM-only, so I'm not really familiar with it (and thus can't offer a good opinion). The 9 series is still pretty good, too; get something 9500 or better, though.
Because I constantly move between two houses, and it's just not an option.
I think I've got a pretty good idea of what I'm looking at now, thanks.