I'm no help for the first question other than contacting generator vendors in your area.
We have only one on-site Kohler generator for IT building protection; would first go to our vendor, TAW Power Systems, with maint. contract on our existing generator and I have one more local contact that supplies Onan generators; also contract with Agility Recovery for widespread outage/business continuity.
In God we trust, all others pay cash. . . Jean Shepherd