It has been replaced by the 940 JM PRO and is no longer in the Mossberg catalog. There used to be a few available at the usual online dealers and distributors, but the events of 2020 thus far have largely cleaned them out. You might watch for one on Gunbroker, but with Jerry's name on the new 940, the old one is not likely to make a return to manufacturing.
The 22" barreled version was a personal favorite. Are you looking specifically for that model for competition, or just the features in general?
Sorry I'm a bit late to the party, new here and stumbled upon this thread. There seems to have been a few online sellers (on gunbroker) that came across some inventory of the 22 inch JM930's; I was just lucky enough to win one in an auction but theres a few that are factory new and being sold outright if that's still on the table for you.