It really depends, as is always the answer to the "best distro" question. I think that it really doesn't matter all that much if you plan on hand compiling your installations, as all distros aresimply a kernel and a selection of packages. The main reason to choose on distro over the other is if you DO NOT plan on compiling your own installs, as the packages and manager is distro dependant. Red Hat/CENTOS distros use the rpm package format, and usually YUM as the package manager in CENTOS. Debian/Ubuntu use .deb package installers with the dpkg manager (which is based on apt-get).
rpm packages are less reliable in IMHO as you can easily wind up in what is called dependency hell (google it), while apt-get or dpkg is a lot better at dependency filling and updating.
If you plan on setting up a single system with a set group of software installed, then I would go with the one you are most familiar with and offers the package versions that you need for the functions you need most, and then tweak it from there.
If you are going for true stability, then it really shouldn't matter, as you should compile your programs by hand using make-install which is available on all distros and will compile specifically for your platform and provide the best stability with any distro also.
This is never an easily answered question, but I hope this helps a little.
I personally prefer .deb based systems, as you can tell for the abover reasons, but with Linux, you should find your own reasons and follow them, as this is what Linux does best, custom platforms suited to your own options.