Easy way to tell is simply by looking at the photos. The model numbers are also different. Corsair LP RAM generally has an L in place of a Z for the third letter (XMS3 is X, Value is V) eg:
8GX3M2A1600C9B Normal Vengeance
4GX3M2A1600C9B Vengeance LP
GSkill's Ares series are LP.
For cooling I would suggest either a CM Hyper 212 EVO
or, if you plan to push it hard, a Noctua NH-D14
is considered pretty good.
EDIT: The GHz edition is a bit more powerful, but the standard 7970 is already very fast. I would also suggest getting an SSD.