Need suggest to upgrade memory for TP2668-4EA

[b:z]

I am using TP 2668-4EA with standard configuration. Currently, my system is using 512Mb (standard when i purchased), and now i want to upgrade to 2Gb RAM in oder to enhance performance.

My question is:
- Which type of RAM should i purchase to be compatible with my system (2668-4EA) ?
- Which brand should i chose: Kingston, Kingmax, Thinkpad/IBM/Lenovo (not sure), crucial, ...?
- Are any different between CL4 and CL5 of RAM?

i also refer http://forum.thinkpads.com/viewtopic.ph ... hlight=ram , but there something i still don't understand.

Please give me your suggestion.
Thank you very much.

[pianowizard]

I bought this dual channel kit from Frys.com for my T43 two months ago and it has been working great. The price is great too.