there isnt anythin spcl about XFX, except for the higher price. Maybe ull get one boxed game free, and it reflects in its final price. XFX one will come close to 8k.
Seriously MSI and Sapphire are great brands.
The resultant fps depends on the game u are playing, ur cpu and memory, detail level in game and driver setings.
For one thing u can be sure of that @ 1024*768 u can max out every details with 2x or 4x AA and still churn more than 50fps, except for crysis and GTA4, which too will give acceptable playable fps at max detail.
And there is actually no need for AA or FSAA for a 17" CRT monotor, if u play at 1280*1024/1280*960 which can be called native[even if there isnt for CRTs].