Plesk
 

Can it be installed on a running box or does it need to be put on a clean box?

Also any other comparable products?

Plesk needs a clean box.

FreeBSD and webmin really is the way to go if you need a browser interface.

Plesk needs a clean box, and if you have half an idea of what your doing you should just use webmin or no panel at all.

Webmin looks shit, is quite advanced, not very user friendly though. Plesk and Ensim are both ok, CPanel does arguably have the most (advanced) options (both reseller and user scripts) and looks real pretty too. Unfortunately the cost of it is very high so probably only of any use if you're a reseller.

Webmin is free as far as I know. If you're no reseller I'd go for Webmin too, unless you're not very familiar with unix based OS's

I was gonna start another thread on this one but I'll ask it here since it's in the same ballpark...

I want to know what's the difference between getting a box with Redhat compared to one with Ensim. I have used Ensim and C-Panel for a while and I am used to the web based control they give. Does Red hat give the same kind of easy control?

RedHat has no remote admin panel as far as I know. An empty box with an OS is just that, and the only way to control it then would be with telnet or ssh.

It's a pain in the ass to install and configure your required software through just a unix shell. If you don't have any experience with unix operating systems, and console mode in particular, you can just forget it. Been there, done that, just install webmin on top of it.