Do I need to buy the same memory ?

[mug2k]

I currently have 4GB (2x2GB) of RAM and want to add another 4. Does the new stick need to be the same profile as the other 2 sticks (DDR3, 1600MHz, CL9 etc) ?

My current memory :-
4GB Corsair XMS3 (2x2GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit - CMX4GX3M2A1600C9

I've seen a 4GB stick which basically the same as above but CL10 for £26 or another stick which the exact same profile (DDR3, 1600MHz, CL9) and £30. Both are different brands to my current RAM.

Thanks,
Marcus