Is it a good idea to start a hosting company, that your servers run on SUSE linux? right now I have SUSE linux 10 on my servers, should I change to another linux? and is vsftod a good FTP server for hosting? if not whitch one is good?
The OS distro you go with should be heavily influenced by your choice of control panel. Many people use Centos (free redhat) these days, but SuSe has lots of followers too.
The more complex decision is which control panel. They all have their ups and downs. Cpanel is the de-facto standard (most common), but can be unstable; others such as DirectAdmin and Plesk are catching up these days. There is a LOT of discussion about this in this board, read up on that before asking further.