Bamt and LinuxCoin are both distros designed for dedicated Bitcoin mining rigs.
LinuxCoin hasn't been updated for ~1.5 years though, and Bamt hasn't been updated in over a year as well.
Bamt is very nice if you can live with outdated software; it provides a nice web interface for monitoring and makes setup as easy as entering your pool login data and any GPU overclocking settings.
Unfortunately I don't think either distro supports Stratum, and ditto for any coins other than Bitcoin. You could use a Stratum proxy but either way you're going to be using outdated software.
Bamt:
https://bitcointalk.org/index.php?topic=65915.0LinuxCoin:
https://en.bitcoin.it/wiki/LinuxCoin