Hi.
I'm thinking of buying this Motherboard:
dabs.com - EVGA Socket 775 nForce 680i SLI ATX A L (122-CK-NF68-A1)

and I want to fit sum graphic card to it. What do u prefer?
What do u think of this one?
PNY GeForce 8800 GT 512MB GDDR3 HDTV/Dual DVI (PCI-Express) - Retail

And what's the difference between card that were made, for example, by PNY or EVGA etc. If my motherboard is made by EVGA, so does my graphic card has to be made by EVGA as well?

Regards

That motherboard should be fine. Graphics cards don't have to be made by the same manufacturer to work on a motherboard, although for SLI, you'll need a motherboard with an nVidia chipset.

There's some evidence that Intel CPUs work slightly better with Intel chipsets, for example, and you might expect this to be the case with nVidia graphics cards and nVidia chipsets too. However, the performance difference will be too small to notice, in my opinion.