I would personally say that MorphOS is a system that has to grow on you. But once it has you will probably like it and get used to the things that are different to AmigaOS 3.1. If a perfect copy of the original in structure is most important, AmigaOS 4 or AROS might be a better choice.
And get a PowerMac G5 instead of a Mac Mini if space isn't a problem. Even the low end 2.0 GHz is fast enough for Full HD video and a Radeon 9600 Pro 128 MB VRAM are plentiful and cheap on Ebay. If they aren't already included.
