>All 060 accelerator boards for Amiga come with an MMU. And all of them except one (75 MHz version of the Apollo 1260, i.e. with LC060) come with an FPU. Lack of FPU means you can't use 060 optimized software that requires an FPU but must resort to soft float 020 or 030 builds in such cases.

So it can be done. Floating point takes a significant hit, but MMU is not 100% necessary.
A lower cost accelerator that would be priced like an '030 but preform netter might be possible.