Keep in mind that the output (wattage) isn't as important as the load (amps). If you're going to install a GPU that requires the 6/8-pin plug, you'll need a PSU that has at least two dedicated +12V rails, with each rail able to support the amperage requirement for your GPU.
My suggestion is to find out the requirments for the GPU, then base your search based upon your budget, while keeping in mind the manufacturers mentioned above. Also worth mentioning is that PSUs with at least 80+ Bronze Certified are viable candidates.
Ahh the 570. Nice choice. Depending on the CPU and RAM, you may find that despite this powerful card, you'll still experience some bottlenecking. Use Newegg's PSU calculator to help with finding a sufficient PSU.
The calculator said around 650w so in the future im going to upgrade so I think I might go with a 750 or 800, but im looking for the ones with multiple 12v rails and all are singles. I'm definitely going to go with the EVGA GeForce GTX 570 GPU. Just a bit confused about the 2x6 pin power conector compatibility with a PSU.