If it was the Pilatus, it would be based in san carlos most likely with a group that takes care of paperwork, maintenance, scheduling pilots and also chartering the plane out (this is one of the major draws for him as the above items can take up a ton more time and money if its not handled by a ownership group that can split the costs where possible between several owners).
If it were a jet, I am not sure where it would be based. I assume it would have to be hangered somewhere much cheaper than the bay area but close enough that the positioning flight to get it back down to SJC or SFO wouldn't be too costly. If he were to get a jet, ideally, it would be great to find an ownership group like the one above that can help out with maintenance, chartering, pilots, etc.
He will probably fly 150-200 hours per year with ~125 of those hours being between SFO/SJC/SQL and KGPI (northwest montana, 9000' commercial airport runway, cold and snow during the winter, 3000' above sea level)