One other thing to consider one vs two axles. My cart only fits through my door with the wheels off so the 2 axles with quick release works well for me. I have small wheels on the back that work as wheelie bars and also to roll it around with the wheels off. Thinking about how you will be moving it around and how you will be storing it might affect how you build it. My first build was a three wheeler that didn't fit out my back door.