Insulation, Radiant and Vapor Barriers - No sub floor; Spray Foam?

I have a 1910 bungalow built on pier & beam with no subfloor and these floors are cold. I've looked at open cell spray foam (Icynene?) but I'm afraid the floors may cup if moisture gets in. Vendors tell me they can spray a vapor barrier coating first, then spray on the foam. Is this an acceptable way to insulate the underside of the house?

Closed cell foam will give you a VB, plus airseal, plus over R7 per inch.

Thank you. I did some other searching & I also talked to another contractor that said the same thing. The last open-cell vendor I talked to said they could spray a barrier coating first, but they didn't include that in their per sq ft price for the open cell. I guess it depends on total cost of vapor barrier spray + the open cell vs the price for just closed cell. If it's close I'll just go with the closed. The slope of my lot means that groundwater leaches under the house on its way to the back yard; after hard rains it can stand for a long time (weeks). This past weekend I went from having 2 small vents to having 5 total, so I hope the increased cross-ventilation will help dry it out. But now even more reason to insulate. Appreciate the response!

Allso if they spray a flash coating on all the wood it will keep mold from growing!