WOW, thanks for all the great replies from everyone.
To start it off, I'm going to go with either the Hitachi 7K500 or 7K750, And I am looking for a nice stick of RAM (4GB). I was hoping to be able to change the graphics card to something more modern, but I was just told in this MBP you can't change the card (please correct me if I was misinformed).
On the topic of a second HDD, my on-the-go kit has 4TB of external storage setup with it when I do a field station for editing, so its really the internal HDD that needs a zippy upgrade, although I appreciate the thought of using a second internal drive.
When I tried to do the 2x2 original upgrade to 4GB from 2GB I got these from Crucial and was told they would work, [2GB,200PIN, DDR2, SODIMM, 256Mx64, PC2-5300] but surely enough the computer won't boot with two, only one and a stick of the stock RAM.
The computer needs to last another year or so, I figured these upgrades would help it last, instead of shelling out $3,000 right this month!