I dont htink you have understood what Richard has done, triple clamps arent expensive to produce (we know we make hundreds every year), do your home work on the engine you want and you wont get burned you dont need to use a special motor/frame combination work with what you have/can get hold of!

Make a list of what you need add a budget for each part and stick to it, it wont come together in weeks/months but neither do the bikes that Richard at Mule makes. The time searching for the parts is where you can save big money, think 2 years to complete and your about there.