Macbook Upgrade Advice

I have a 2 1/2 year old 13" Macbook (aluminum unibody) 2.0Gz, 320GB HD, 2GB ram. It's starting to slow down and needs more HD space.

Hard Drive questions: Thinking of a 500 or 750 GB HD. I think it will support 7200rpm. Would I see much benefit from this vs. 5400rpm?

RAM questions: I believe with the right boot ROM version it will support up to 8 GB of RAM. I sometimes work with imovie, mainly with pictures and music but sometimes video. Otherwise not a lot of memory intensive apps. Would I see much benefit from 8GB vs. 4GB?

Also, I would like to move some programs that I no longer have install discs for to new HD once installed. What's the best/easiest method?

I'd appreciate any advice and any other considerations I may need to think of.

Thanks

when u are going to upgrade the hard drive use the program called time machine that is build into the mac, using an external hdd it wil back up ur user setting and ur programs and files eg pics music ect.
then install the new hdd and install mac os, then when seting up ur mac with user name ect it will say start as new pc or restore from time machine use that and it will put it back to how it was before u changed the hdd , and as for the hdd speeds 7200rpm will be a lot quicker in the load times of ur programs and booting up,

Thanks

Thanks Chris. I appreciate the help.
2 more questions. Using the time machine method to transfer programs/settings, can I pick and choose just those that I want or do I have to install all previous programs/settings.
Also, any thoughts on the question of 4/8GB of RAM.

as far as i know when i used time machine to change my hdd it just added all the setting and programs back, there might be away to modify it not to sure tho.
my mac book pro 2011 model has 4gb ram and its pretty quick has some powerful programs on it and a 500gb hdd nearly full, it boots up in 23 seconds and shuts down in 2 seconds, so for me its more that quick enough i was going to upgrade to 8gb ram but dont think its worth it atm, i would try 4gb ram and see how u go, but personally 4gb would be more than ample

Thanks Again

thats ok good luck with the upgrades