Send me a PM, I think one of the guys in our yard has a P-18 Mast if that will work for you. May require your coming to So Cal to get it. IMPO - Of course they are to going to recommend it, opens them up liability.

You can put a 16 mast on an 18, a 18 mast on a 16, a 19 on and 18-2 etc.....