If you're going 64 bit, I found 8gbs so much faster than even 6. Go Mushkin. Great for overclocking, durable, great rep. and lifetime warranty. Get a 2 gb kit for the old system and when you can, bump up the Mushkins you have to 8gbs, and stick with the same speed /make though I've mixed manufacturers before wit hthe same timings. I couldn't believe how much faster the last stick made my system. Enjoy!
