Over the past few years, I have maintained an installation script for ISPConfig3. The script is hosted over on Github, ISPConfig-3-Debian-Installer, and I recently made a few changes to it. I had wanted to make it just work better, and a few issue were submitted in a row that made me take a look at it again. It now works in just one file, and I think that is the biggest improvement. If you have an empty VPS or Server, you should give the script a shot. The control panel that it installs is pretty cool, and it is actively maintained over at How To Forge.
If you use the script and find any issues, feel free to send me an email here or open an issue at GitHub. Either way, I will take a look at it.