Pure Rocket,
I had a feeling you might run into problems and I hope LOTR's advise has solved that.
My guestimates for what I need to run limewire are pretty much borne out by LOTR
At one time I had 1.2 GB free space on my start up disc and on a heavy LW session I would get warning messages to free up memory and once or twice the Mac crashed completely (not a common occurrence on a Mac OSX) so I recon 1.5 GB should be free, at least, for the Virtual Memory. That in effect leaves you with 1 1/2 GB free space, which is not going to accomodate a lot of downloads unless you are planning to burn them all to disc
As for the ram (which I confess I am not very clued up) LOTR is using in his illustration more (just) than you have available, so yes, it looks as if you need a bit more!
I find things sometimes slow down to a crawl and I think increasing the RAM would improve this as would a faster processor ... and I do have a very reasonable sourse of supply which is very useful. You must, as I said before, cultivate a new type of friend
I think you can get hard drives pretty cheaply .. but you and I don't really have any idea if they will be alright with out a bit of expert advise.
Let us know how you get on ...........