Yeah they sell everything circus / extreme sport. Unicycles, Diablos, Fire breathing kits, Bocks, Skate boards blah blah blah.
Actually Finsbury Park is big and suitable for meets. Even has a skate park in it.
It also has a boating lake, running tack, American football pitch, tennis coarts ,picnic areas and play areas as well as a cafe, dog training facility, art gallery, gardening area, play school and art centre