The 912 looks like the way to go for a motor, though the new Brazillian VW that was at Oshkosh looked interesting. How much have builders spent on their 912's and is there any difference between certified and not, other than paperwork. Are these motors discounted, or can you plan on paying list price, and what does a prop cost? Other than the Kitfox firewall forward kit, 912, and prop, is there anything else to buy?