Well,the thing is,and alot of people dont really know it,the 68000 is a 32 bit cpu.There are different versions of the chip,and the Neo got one of the better versions.The audio is Yamaha based,and is damn powerful.Considering you get those 2 combinations,plus a Zilog 80 cpu,a really great custom graphics chip,and depending on how much ram chips you can afford,Im sure it couldnt be too hard for a skilled person.There is plenty of documintation on the instruction set for the 68000,both its 16 bit and 32 bit instructions.They were still making this cpu up untill 2000.
Someone was selling a eprom host board set for MVS to debug,it was the guy who made that Super Bubble Pop game for MVS.You could always get into contact with him for more info Im sure.
Side note,as Im not sure ho wmany of you know about this,but you can overclock the Genesis systems 68000 to reach the 12mhz of the Neos cpu,or go beyound that speed to 23mhz if I remember right.At 12mhz,flicker and slowdown on Genesis games is about all but gone.There were a few people on the net that offered to mod Genesis 1 decks that were oc'ed.The info on how to do this is still around Im sure.The same can also be done on the N64 systems cpu,as you can clock it to 99 mhz from its original 66mhz.
You can also oc a Dreamcast system to get rid of lag frames per second,but its not easy.Not every DC motherboard will accept this overclock,and sometimes the ram chips will pop off the pcb.They used Sdram for the system,and sdram is not very friendly abou tbeing overclocked,which happens on that system when you oc its Hitachi based cpu.