I recently had to setup CentOS 5.1 x86_64 on a remote Hetzner dedicated server . CentOS is not listed in the supported distributions but that's not a problem, especially if you have already played with the remote vnc installation mode. The only problem is that their dedicated servers have a newer Realtek Gigabit controller that is not supported by the CentOS 5.1 kernel (from `lspci`: RTL8111/8168B PCI Express Gigabit Ethernet controller ). But the good news is that a driverdisk is available on the CentOS Wiki.

I choosed to setup a minimal Fedora Core 8 (supported through their web control panel) and from there modify grub to launch the CentOS 5.1 x86_64 setup. I was thinking writing the 'step-by-step' procedure somewhere on the wiki but i've found that such procedure (even if i didn't follow it completely because i installed first and quickly a minimal Fedora core 8 ) was already written by someone else on the Hetzner Wiki . My advice : add the 'noipv6' parameter to speed up the installation and avoid anaconda trying to get a ipv6 address through dhcp (see my previous note)
The other good news is that they have an internal CentOS 5 mirror so the setup is really quick because on an internal Gigabit network.

Of course such procedure should only be done by people who have already installed a box remotely and understood the way a remote setup works. My advice is so that you test such procedure locally in your lan prior to 'test' it on the remote server.

Anyway, if something went wrong, you still have a possibility to remotely reset the server and boot it up through pxe in a rescue environment (based on Debian Etch)