So, it sounds like it's possible that there isn't really a 1200 specific project that's feasible.
What most people would want, cheap RAM/Accelerators, can't be cheap.
On the high end, you might be able to do a 68060 setup, but the small market would mean they'd have to charge quite a bit for it...
And, with products like the FPGA Arcade and possibly Natami coming out, it also makes the high end market a tough sell..
I like the FPGA Arcade's chances as it has a larger market... Home Arcade machine owners also will be considering those, as well as other hobbyests can use the FPGA Arcade, so it's not limited to an Amiga audience, which I think will help.
Of course, it will be nice to be surprised on this one.. ;-)