Ramn that I should get for OC my pc

I have Nanya Technologies Ram I already posted that my pc is not stable
[email protected] Ramn DDR400- My Friend recommended that I should get new ramn so I did my search with his help and here is what i came out with.

Here is what my friend recommends eather:

OCZ Enhanced Latency Dual Channel 1GB DDR PC-4000
Speed: DDR500
Cas Latency: 2.5-4-4-7

Or

Mushkin Dual Pack 1GB DDR PC-4000
Speed: DDR500
Cas Latency: 3

I saw more ram but i think one of this 2 should be good.
Any sugestions will be greatly appreciated