I need a 3-speed hub for a 20" kids bike that is an aluminum frame so stretching is not an option. There are some older 110MM hubs around and I don't know which ones to look for or avoid. I would like to stay with 36 spokes but not the ultimate deal-breaker.

I want to be sure whatever hub I find that the shifter travel coincides with the hub. Obviously a built wheel with the hub would be great, must be 110MM though.

Wanted to edit that it needs to be a coaster brake.