Spray foam insulation, attic: thoughts, contractor recs?

Hi. Ceiling is wooden tongue 'n groove slats; some have gaps between (old house). Attic heat is escaping a bit, obvi. Has blown insulation in there already. As a result, there's some sweating/dripping occurring in 3 spots (and has been for some time, although not on the seller's disclosure). This happens when the temp differential is extreme (when tenants moved out last week they left the thermostat on 68). Already had an AC guy reseal around the vents (helped, but not where the other drips are).

SO his thoughts on options are:

1. Caulk between the ceiling gaps. // This seems heavily labor intensive, unattractive aesthetically, and not the best fix.
2. Spray foam insulation in the ceiling' perhaps putting down some plastic liner between the foam and the wood so that foam doesn't ooze through the gaps. // How toxic and off-gassy is this stuff? It has to be a certain type of foam, yes? Thoughts?
3. Sheetrock the ceiling. // Also unattractive aesthetically; loses some of the recycled material artwork (designs w corks), everything needs to be rewired.

Thanks in advance!! It's not a big house, so I'm hoping it's decently affordable to fix.