Doing some sort of equivalent would be very expensive. I imagine getting the chips and redesigning the PCB and its traces could be a lot of money.

Doing an FPGA version would also be the same. People can barely do FPGA accesible for the N64 and PSX, and even then I think there's limitations with those implementations.

Boards trims of the Wii seem very plausible as the hardware wasn't as complex as other consoles from the era. I have no idea about sizes, but there's a chance the Wii has a smaller processor thanks to die shrinks.