It has to be an Amiga OCS 1mb chipram machine built into a joystick like the C64DTV thing and sold for $30 or less. Also to include 30 iconic Amiga games in the flash rom. Just like the 64DTV you can add register compatible enhancements to the chipset too like a proper byte per pixel 256 colour mode (and therefore a 3 byte per pixel 24bit mode etc) and triple Paula emulation for 12 sound channels (or 6 14bit sound channels).
Anything else would be doomed to obscurity IMO
Yes an Amithlon machine running properly on an 8 core version of the Intel i7 and the hottest GPU currently in development would make an amazing machine but would anyone buy it to cover the development cost of rewriting 0S 3.x to run properly on it and even 1 game of Playstation 4/Xbox One quality (without a PS4 quality game the system is useless, games prove in seconds who has the most powerful hardware today and ultimately why Doom not being as good on mhz per mhz with cheap PCs is why AGA died a quick death....and took C= with it IMO).
(I have no interest in PPC, neither Morph or OS4 have a future running on such a CPU once all the bespoke/old Mac host hardware disappears)