Okay, so lets say we go for the 7850.
My Specs are:
AMD FX-4170 (OC to 4.0Ghz or 4.4Ghz)
AMD HD6670 (2GB)
I'm not sure what PSU i have :S, but on the back all it says is "AC 230V" I think it may be 500W but really not sure
Thanks for the replies so far guys