Every day we field calls about financing the weeHouses, not just building them. With a couple dozen + under our belts, we are comfortable recommending a few lending sources (although we always suggest you work with your local bank/lender first). Here's a .pdf from one of the East Coast lending sources: American Home Bank, that I thought I'd share. Hope it's helpful!
P.S. In case the .jpg is too hard to view, their Web site is: www.systembuiltmortgage.com.