Ouch. You can use Gentoo and get the pre-compiled version (GRP). Or compile it yourself if you have a month to wait for it (literally...). Nah, I'd stay away from Gentoo.

There are distros made especially for slow computers. http://www.vectorlinux.com/ for example. Or http://mulinux.sunsite.dk/ . Slackware is pretty good, but hasn't released a new version for many many months, so it might be dead. RedHat and Mandrake offer minimal installs too, don't they? I've read about people using Debian on machines almost as slow as yours. Honestly all distros are probably about the same. Linux can run fine on a 386 even. You should just try a bunch till you find one that works OK.

You're not going to want to run Gnome or KDE though, with that slow a computer. You'll probably want to use Fluxbox/Openbox, or at the very most XFCE4. But those are available for most distros, pretty sure.