You can run any single PCI-E card, but you cannot crossfire. The chipset only determines crossfire or SLI, in respect to GPU.
You can SLI, but really you would be somewhat limited by the CPU. I think either of those cards you have chosen are pretty nice for the price. The GTX 260 I linked is a faster, newer version than the one you have linked. 216 processors as opposed to 192, and it does make quite a difference.
Still I think it's kind of cool that all the cards we've listed pretty much reflect a good cost/performance ratio. It's been a few weeks since I looked closely. Choose what you can afford and you should be happy with the results.