well.....I have only used fiberglass to work on a sub box in my spare tire well. I used chop mat, since I needed it for structual integrity, and it didn't have to look nice (all covered up).
As for the foam, I know what you are talking about, but it escapes me at this point in time, as well as the gold filler stuff.
About resin, I do not suggest bondo branded resin, you can't keep brushes from hardening up in acetone with that stuff.....but I am going to keep using it since it was $30. From my own personal experience, 1 gallon of resin per 5 square yards of glass is what you need....and I got polyestrye (sp) resin, don't know about the ratio stuff