Please keep updating this thread. When I considered building one, I was looking at the UL Power engines.
Will do.
When we first started looking into the powerplants for this, we were leaning UL Power too, since that's kind of what Zenith pushes. Aero Momentum was another high on the list, and Viking was pretty much at the bottom of the list. After meeting with all the vendors and reps at Oshkosh, Aero Momentum went to the bottom and Viking went the the top.
We also met with a guy that flew his Viking powered 750 through the lower 48 states on his way to Oshkosh from Texas in 10 days. Met up with him again a few months later at the Zenith homecoming and went for a ride - way more fun than the ride I took with Roger in the UL powered Cruzer LOL.