That stage rig puts the weight up high. When you break it back to roll it, it puts a lot more weight than necessary on your arm (handle is way too small for two hands). You want the weight as low as possible. And you don't want to put a $1000 amp on a dolly you can't control with 2-hand leverage if needed. IMO, of course.
For less money than the stage rig, I'd get the Harper truck above, some cheap ratchet straps, and a good amp stand.