You can do it well with a better system.
My linux/box is a laptop with Pentium3 600MHz, 192Mb ram and external 500Gb usb hd.
I use a very light slackware + amuled + amuleweb + telnet.
It runs fine with a lot of file/sources, and it use more or less 46% of memory and 1% to 5% of cpu while downloading/uploading; but i have one only big problem... USB 1.1 port!
When amule has to hash a new file or is completing a file it "freeze".
amule stop every download and upload.
