560Ti, 1 or 2GB? Or 570? Or ???

[Dano]

I'm all ready to build a new system, I could even pop down the local emporium this afternoon and get all the bits having decided on everything bar the gfx card.

The plan is a 2500k, motherboard to suit, 8GB ram and a gfx card to go with, my bro has the Twin Frozr 560Ti which runs ILCoD pretty darn well but it only has 1GB ram on it, do I get the 2GB version which isn't overclocked and sacrifice some raw speed for more memory or do I get something completely different?

My head is about to explode