I am waiting to have spray-foam insulation installed. If I use traditional fiberglass and a radiant heat barrier, I will then have to pay to have it removed and disposed of, prior to the spray foam insulation.

There is a soy-based spray foam insulation I plan on having installed.

http://soythane.mybigcommerce.com/

http://www.biobased.net/

A bit more expensive, but I believe it is worth it.