To be perfectly honest.

None.

But if you want to look at cards to flash then imo getting a used PC GF6800 GT or so might be doable for non-insane cost. But you gotta flash it yourself otherwise you will be looking on ebay and last time I saw(ok, 2007/2008) people wanted like, $200-$300 and more for pre-flashed cards like the Radeon x800/x850, GeForce 6800GT/7800GS.