This section of the forum is pretty much dead. If you just want something to play around in a parking lot, I'd say you're fine getting just about anything, and throwing some bigger tires on there.

While I'm sure this is great for balance, more time in the lot on your stunt piece is going to make you a better stunt rider, not playing on a bicycle. I rode for a while, and it just takes time, the BP on a bicycle isn't going to be the same as one on a 600cc sportbike.