Hello Scarab,
You might want to try out the unregistered version of MorphOS if you haven't already. If your Mac Mini hits a snag it would be nice to find this out before paying 250 Euros.
http://www.morphos-team.net/ has the downloads there for the ISO image.
I'm a developer for the Mattathias project which is an attempt to bring AmosPro software to modern machines using LLVM as our code generator. If you would be willing to try to port
LLVM to MorphOS, I would be very grateful. Especially since I think MorphOS is stuck with an out-of-date version of GCC in many cases and Clang makes a nice C compiler. The Mattathias project mailing list page is at
http://tech.groups.yahoo.com/group/mattathias/. If you are interested in joining the team make a mention there.
Welcome to Amiga.org. You might want to check out
http://www.morphzone.org/ also, if you plant on using MorphOS.