I went with 2 6 volt batteries on my RV and am considering changing my 12 volt batteries on the boat.
The 2 6's on the RV work out fantastic and seem to last longer than when I had 2 12's on it.
http://www.ccis.com/home/mnemeth/12volt/12volt.htm
I agree; Just an idea Dave, why not have someone solicit the local Resturants, Hotels/Motels, Tackle Shops, and Retail Stores in the area for donations. It seems a small amount to ask for the benefits they enjoy also.