Thanks for help guys. But I was looking at something a little cheaper like the Inspirion 1300 from DELL but I don't know what configuration to choose, here is a link to it:
The only thing is it comes with 256MB of RAM and I reckon I need 512MB but its an extra £55 (~$100) for an extra 256MB on DELL's site. So I will probably buy the 256MB DDR2-533 myself afterwards.
Edit: How much do you reckon I could sell my old...