Hey Charlie, congrats on the new mower! I saw those a few years back and thought they would be a great mower for someone with a lot of slopes to mow, or for someone who just wasn't comfortable with using "control sticks".
I didn't think about the "one arm" advantage at that time, but the mower looks like a "fix" for that problem as well.
Be sure and let us know how you like it when you get it, and then give us an update after using it a while.
I'm like you about the replacement parts. From what I saw the GizMow uses components that are commonly used on other mowers, so I wouldn't worry about that too much at all. Which engine did you get? (I don't remember what engine(s) were offered).