I would suggest an Amiga, which looks and feels like an Amiga but an evolution over the classic Amiga in both looks and feel.
The hardware should be generic legacy pc including an Intel CPU but with a special custom bios which will have an Amiga look & feel to it instead of a generic PC feel.
It should come bundled with a x86 specially written version of OS4 and the BIOS can also serve as a sort of protection so that OS4 can ONLY run on x86 machines with this BIOS.
