I've mentioned it a few times in these threads, but it's worth looking at Webmin/Virtualmin. This is what I use for a few customers' websites.
It essentially uses plain Debian / Ubuntu, and then uses a GUI interface to interact with the standard configuration files of all the apps (Apache, Postfix, Mailman, Bind etc etc.)
So it's not a modification of the distribution, but more a tool to manage it.
I have not used Symbiosis, but I guess that it won't do so many things automagically for you, but it does take away a lot of the poring over complex config files from you.
You can add Webmin / Virtualmin to an existing system, or the preferred route is after a clean install. They provide a shell script installer that checks that you have everything installed to run all the bits you need for a hosting setup.
It may not work well on top of Symbiosis though.
I'm pretty happy with it, having used it since around 2009 ish.
it doesn't take you away from the fun of distribution upgrades every couple of years though!