Those specs are fine for OS 4.0, no need for a 3GHz duo core or 4GHz P4 for it!
OS4 is pretty dead, perhaps OS5. True, you do not need a modern x86/x86_64 to run any of the Amiga like OSs out there. Problem is paying for high end x86_64 and not getting much of anything for your money. Now if they can get a mobo and OS for way under $200, then they may have something. However, if they continue as is, it's not going to fly.
Dammy