GXT-120 PC version ok or macvideoguys

I already bought a GTX570 Mac card from the macvideocard guys wich works great, and now want to update my other card to a GTX-120. Can I buy a PC model one, since I can use the 570 for a boot screen, but I am connecting both monitors to the 120.
It seems that the PC version cards have up to 1 Gig memorry and DDR3 ram. The MacVideoCard guys only list a 256meg card.
Christian
It seems that the PC version cards have up to 1 Gig memorry and DDR3 ram. The MacVideoCard guys only list a 256meg card.
Christian