Upgrading Hard drive and RAM Questions

Hi,

I already ordered a 640 gb samsung spinpoint, and plan on replacing the 320 gb hard drive in the MBP. Would the best way to transfer the data be to use time machine to create a backup and then load that to the new hard drive?

Also my macbook pro is a late 2008, 5,1 model. I've been told it has a 6 GB maximum capacity for RAM, but I have also read that there is a way to get it to accept 8 gb RAM, any truth to this. Also, what RAM would you recommend purchasing and from what trusted site would you refer me to? Are there any sites with scanners to tell me?

Thanks for all your help everyone you have been great with past questions.