this topic is a few months old but i'll put this info here anyway.
centos 5.5 32bit as far as i know openal doesn't install on it's own and i atleast had to install the nvidia drivers to get that going but other than that it's a very stable dist.
openal installs there and is functional

it's basically the same as Scientific Linux 5.5 which I've been using.
anyway note that rhel isn't fully supported atm as it doesn't meet the minimum glibc version (it has 2.5, minimum for ps is 2.7).
it will most probably still work, anyway, as the only function that isn't in 2.5 is not used afaik (sscanf used by ptmalloc which is not used, but still linked by some cs lib), however I'm not 100% on that one.