My 2 cents... Go ahead and get that PPC accelerated classic Amiga and run 3.9 and/or 4.1(classic).
As for MorphOS, it seems a better experience to just get required MAC hardware and run their latest release. The grapevine indicates a new 3.0 version coming out in the near future. If it is like any of their other post 2.0 updates, I'm sure you wouldn't be disappointed.
