I have an eaton m90 I would go cheap. I was going to mount in where the alternator goes and put the alternator in place of the compressor. I also have a pulley that fits the M20 for it. Custom brackets, intake and charge pipes would have it running, and a supercharger is a good candidate for a BEGI FMU and 21# injectors for fuel management.
The eaton I have needs a new front seal and oil, but you'd do that with any used SC. Rebuild kits are cheap, like $50 or so.