Webmin really is the best admin tool if you don't need the fancy client-side features. It is modular and extensible, and comes with tons of features.
As for automation, you can install a module called isp4u to automate things a bit.
No other control panel comes close to the functionalities of webmin, and to my knowledge, most of them don't allow you to integrate new scripts. (You may be able to do so by re-skinning cpanel and adding links to your own scripts).