Webmin is a great package for setting up servers and users and such, but webmin is a package designed more for root to be able to control the whole box from remote locations, and it would not
be a good idea to give access to Webmin, I am also searching for a good CP for hosting and have come up almost dead ended.
i have installe cpanel(www.cpanel.net
) which is sweet but pretty expensive (im on a 15 day license), another option is ensim Webppliance, which in my opinion is not very robust but does work.( ensim doesnt give out demos or even have online demo), or plesk which i just found and played w/ online demo, which didnt seem all that great and not sure about there user interface.
I hope i have helped some and if you come across a cp that works and is cheap ( or FREE!!! even better) please send me an email.