20" Unicycle for Basic Street/Flatland Tricks - CPH, Denmark

I want to start learning some basic street/flatland tricks. We only have a 24" and a 29" muni right now. I want to buy a 20". It does not have to be in the best shape, but I would prefer that it not require much work (otherwise I might as well buy one new).

I live in Copehnagen, Denmark. I would really prefer to buy one from someone in the CPH area if possible.