Mission is key, but on a homebuilt budget, you pretty much have to follow the engine; you got the Lycoming/ Continental line, you could move up to a Russian radial, maybe a 985. After that it silly season with turbines. We can start at 1/2 VWs and follow what is successful by average success. The line is very narrow. The thing is, someone has already been there before you. No new ground out there. You might be thinking you got a fresh one idea, it’s not. You can hang yourself on a need, but we don’t have the clout. You pretty much have to fall in line if you want an airplane. .005% might pull off something else.