This is sort of something major to think about. There are plenty of people that would want to set up a server but lack the skills to do so on an arch Based system. Of course rolling release is never the best idea for a server, it can help someone who wants to ‘play around’ and learn a few things.
As a starting point, I would really only focus on LAMP. Once everything is working as it should, you can start adding other services. It’s never a good idea to start out feature rich, you end up spending too much time smoothing out issues instead of perfecting what already works. Once you get one set up and perfected, more can be added later. Personally, LAMP is not my go-to server either but I know that it is one of the most straight forward services that can either proof a concept here and establish a need or could simply prove that nobody uses it and it was waste of time.
I do think that this whole idea would work better if it were NOT a profile. User starts out with a bare install and use meta-packages or install scripts to install packages and configure. Creating install scripts that guide them through the configuration changes and explains what is being changed might serve the user better as it will not blindly set up a server that they know nothing about.
Just my opinion on things, Chrys, decide what you feel would be best and when and where I can, I will be glad to help. Maybe you and I can tackle a Dialog configuration utility that can get this working proper.