Good video card for an HP Pavilion p6774y with a PCI-e 1.0 port?

Hey guys,

I want to upgrade my video card so I can play Diablo 3, and the radeon 7750 is looking like a good bet. The problem is, there's only a PCI-e x16 port on my mobo, and most solid vid cards I've found are 2.1 or better. Research I've done says that it SHOULD be backwards compatible, but I don't want to waste the money if it isn't going to work.

Mobo: N-Alvorix-RS880-uATX (Alvorix)

Thanks for the help in advance