you know what would likely run great on that box?
College Linux - it's only one iso to download and is known for being fast on even older machines.
if you're interested, you can get it here:
the only thing you need to do is create your own partitions, but that's easy, you can do that with the install cd - all you need is a swap partition that is the same size as your ram and a / root partition, then you are set, the rest of the install is supereasy, just pick the easy mode where you can.
I have started a guide on it - you can access that by going to my guide below. Check out the main guide for instructions on installing too.