I suppose that you are talking about the Corsair XMS2 TWIN2X4096-6400C5DHX.
Corsair is a better brand (although Gskill is very good too), but you will get a better performance choosing the G. Skill F2-8500CL5D-4GBPK DDRII modules (1066Mhz CL5)
A good option from Corsair would be this one:
XMS2 TWIN2X4096-6400C4DHX (800Mhz CL4)
Anyway, take a look at your mobo's "qualified vendors list" (QVL) for not having any compatibility problems.