Graphics Card Rec...

I will be purchasing a graphics card soon for my new build, I was going to get a GTX 680 but it is pricey, should I just splurge on the 680 or is there a cheaper option that is just as good? Budget is 600, but I would like to save if I could. I plan to be playing GW2 and other MMORPGs.

This is what I have:

Asus Z77-Pro

LP Corsair Vengeance 8 GB

I5-3570k

Noctua NH-D14

NZXT Phantom Full Tower

2Tb Western Digital HDD

23'' Monitor 1920x1080 Res



Also I'm unsure what SSD is best to purchase, I just decided it would be best to purchase one. I am also unsure about my PSU. What should I get if I do intend to OC and SLI later? Id rather pay a lil extra for a higher wattage just to be safe.