An external drive for my MacBook 13-inch Aluminium (Late 2008)

Question

My 250GB x 2.4GHz MacBook with 2GB RAM now only has 87 GB available. I'm sure that the main reason for this is the 15,000 + images I have saved in iPhoto. Of course, it's pretty slow to do anything at all these days, too, so I'm thinking I'll take advantage of a few days off to 'renovate' my MacBook.
I would be very grateful if anyone could advise whether my thinking is correct or a bit wrong ....
First, I would like to get an External Hard Drive (Macpower SK-3500 S2 eSATA/USB2.0 - 1.5TB) and move ALL my images from my MacBook to this external drive. I would also like to partition this external drive so that I could use it as an additional backup drive (in addition to my 500GB Time Capsule).
I would then like to do an 'Erase and Install' and update my OS to 10.6. The reason for the 'Erase and Install' is because I (stupidly, because I didn't know what I was doing) chose to format my drive as Mac OS Extended (Case-sensitive, Journaled) which causes me all sorts of problems whenever I have to access any Adobe created documents because it simply refuses to print them (Adobe says that it doesn't support any Case-sensitive formatted drives).
So, if I free up as much disk space as possible by putting all my images and, perhaps, all my iTunes music on the external drive then re-format my drive to Mac OS Extended, Journaled and install OS X 10.6 should my MacBook become a snappy MacBook once more or is it doomed to be slow for the rest of its life???
Any suggestions would be very gratefully received.
Cheers

Answer 1

You should increase the size of your memory (aka memory). I upgraded to 4 GB. Your MacBook model (same as mine) was tested and found to hold up to 6GB of memory.
I recommend this upgrade before upgrading anything else. I highly recommend http://www.macsales.com/ for all purchases. You should plan on spending around $50 for 4Gb (2x2GB) or $100 for 6GB (1x4GB, 1x2GB). The more memory you have, the faster the laptop will be.
Upgrading hard drive can only speed up the MacBook if you buy a hard drive with a higher number of RPM than your current hard drive, such as going from a 5400RPM to a 7200RPM. The fastest hard drive you will find will be a SSD (solid state drive), but they are much more expensive per GB than typical hard drives because SSD's use flash memory. The Crucial RealSSD C300 256GB costs about $600, for example.
Before any purchases, check to see what hardware is compatible with your Macbook, then read reviews of this type of product that is within your price range.
FYI: The storage (aka hard drive) and memory are the only upgradable features on this MacBook.