RE: The better engine
I have the plane. My suggestion is to use a g-62. Will fit into the cowl with aftermarket muffler. Lots cheaper than a ZDZ 50, lots more power, which is never bad, no nose weight needed if built to plans. I fly at 5,000 feet so I would expect your plane to be more overpowered than mine so maybe a G-45 would be a good choice.
Larry