Floor Replacement Help (lots of it!)

I recently purchased an 1989 Bayliner Arriva. She is trash, but really want to help bring her back to life. Started with the deck and tore it out because the floor had several soft spots. Removed roted wood and fiberglass and am working on replacing. Left myself a good base to replace the floor (about 2" lip). Have removed rot from stingers but going to attach new stingers to present ones. build myself generic stingers with L brackets and attach wood cross bars to support new flooring. Am going to replace old cut out floor with buoyance foam over current foam to replace 3/4 old plywood where I cut the old floor out.

Going to use MOD 1/2" I found at my local Menards. Then going to seal it in with fiberglass. Do have a few questions. Found 18oz Fiberglass cloth on ebay Yes I am going to screw my new stingers to my old and fiberglass them in. My questions are, how much resin will I need to seal my new floor? I have read not to use polyester, and read that I should use polyester. I have read I should put two coats of resin on the bottom of the MOD but not the cloth, and read that I should put one coat of resin and then the cloth and then two more coats over that for 4 coats on the top. That's a lot of resin. Any ideas if what I have read is correct and can someone give me an estimate of how much resin I will need?

Oh does someone know a good reupholster? That will immediately follow the carpet.