I would always prefer a good single card over a dual card configuration.
You may lose some benchmarks, but you will have less lagging.
A FX-8350 is about a $200 cpu. My rule of thumb for a balanced gamer is to budget twice the cpu cost for the graphics card.
In this case, $250 buys you a GTX760, $420 buys you a GTX770.
And, for what it is worth, I do not consider the 8 core FX-8350 to be a great gamer.
Games rarely use more than 2-3 cores. A stronger quad like a i5-3570K or i5-4670K in the same price range would be superior.
If you are okay with overclocking, the Radeon HD 7950 overclocked will beat the GTX 760, and sometimes even the GTX 770 overclocked.
It is only $250 right now for a good sapphire version of the card.
If you do not want to overclock, then get the GTX 760 or GTX 770. They are good stock cards.
Also to Geofelt, with the Xbox One and PS4 being more like computers than consoles ever have been, and both running on 8 cores, I would think new generation of games would start taking advantage of the 8 cores when ported to PC.
Overall, the i5-3570k vs. the FX-8350, the only thing the 3570k really wins at is single core performance. The 8350 for the typical user (gaming, watching youtube, listening to music, etc.) the 8350 will deliver a smoother experience with applications becoming more and more threaded.
"And, for what it is worth, I do not consider the 8 core FX-8350 to be a great gamer."
Well weather you "consider" the FX-8350 to be bad or good is really mute the fact is the FX-8350 is a very good gaming CPU with no question. I have a FX-8350 based rig and a i5 3570K and would have no problem putting my AMD rig up against my i5 in any game out there. On both of my rigs I run a Eyefinity/Surround on 3 Asus 27" monitors and and both can maintain a constant 60fps vsync'ed at 5760x1080 on ultra/max settings. What else would you need.