The only system I wouldn't really recommend is Mac OS 10.1. The compiler support is pretty thin and there's no Python 2.1.3 binary... from what I've heard, this is better in 10.2.
i'm not sure what you mean by "compiler support". OS X 10.0, 10.1 and 10.2 all have complete developer packages you can install with compilers etc. there really isn't much of a difference. as far as python binaries go, if i set up a production-level machine i would never use built-in binaries, anyway. you also point out that you would roll all software yourself, so whether the OS has a python binary or not does not matter. neither of use would use it. i fully agree with all other recommendations you made. for our larger installs we have "standardized" on RedHat 7.3 as the base operating system. jens