Questions Regarding This Rig

WARNING:
These questions/post is from a noob when it comes to making a gaming rig

Okay so I am thinking on buying a new pc after 5-7 years! Unfortunately my money is a little limited at the moment so I could just afford these specs. However I am concerned about these 3:

i5-4570
MSI Z87-G43
INNO3D GTX660 192bit 2gb GDDR5 special fan cooler something (Not the TI version!)

I will be primarily using this rig to play FF, and other inc pc games.
The monitor that I will be using has a native resolution of 1366x768. (I am not in the market for a new monitor atm and I am fine playing at this resolution)

Questions:
What settings do you think can I play FFXIV on this rig without me suffering massive FPS drops? I was hoping I could get up to high settings with consistent fps at 50+.

I also read somewhere that this mobo doesn't support SLI, but does support Crossfire. I haven't used an ATI card before and atm I don't know how much the INNO3D GTX660's counterpart in ATI is.