Gentoo rocks. Installing Gentoo is a wonderful learning experience and it's the most flexible distro out there -- especially if you need to run a patched userland.

Not mentioned: Gentoo Prefix project is useful for managing a Gentoo installation that is at a path other than /. We use it for building our Linux development environment.

See [1] to give it a try. Warning! It will compile almost everything so it's going to take a bit of time!

[1]: https://wiki.gentoo.org/wiki/Project:Prefix/Bootstrap#Perfor...