I built one with a rack mount chinadoll on a full suspension mountainbike which could just as easily have been installed on the front wheel with a few mods. The ragjoint sprocket does not care which wheel it is on. My setup DID require welding though.
It ran like a champ and was very comfortable!
Here's a link to the build thread:
If more is better, then too much is just enough.
If you can't afford it, build it yourself.