One of the disadvantages of having the best weather in the world is inability to get good insulation foam. I have been practically told that I am insane when I have asked for it at Home Depot or other home improvement places.
I have only found it successfully at one place but the price seemed sorta high and it was pretty thick.
BUT there is some hope. After posting on BoLS' new form I was pointed to these guys:
http://www.bobsfoam.com/ and I think I might drop em an email for pricing today. In the past I had heard of them before but was told that it burnt down. Luckily it seems to be safe and still in business.