Hey, I resemble that remark!
(Actually, no, I rarely suggest that FPGA are the way to go.)
One of the useless gadfly suggestions I've tossed out there from time to time when someone complains about the lack of storage options for the original (pre-Plus) machines is that someone write a Macintosh driver for those extremely simple 68000-socket piggyback IDE ports that the Amiga and Atari ST people seem to churn out in vast quantities. If you ever succeed in your IIsi ROM hacking... if anyone on this board is qualified it's probably you.
Anyway, I wish I could do that sort of thing myself, but:
A: I have barely enough hobby time to wrap my moldering old brain around the software complexities of my Commodore PETs. The Mac toolbox is just a big scary blur to me.
B: My oldest Mac is a B&W, and I'm probably going to pitch that in the recycle bin one of these days. Toaster Macs just ain't my fight.
I do know just enough about hardware to tentatively say that doing the hardware for a 68000 Mac should be something doable at the hobbyist level. '030 and faster PDS and Nubus? That's pretty hard stuff.