Ooh the bet spar sounds fun! But not sure about street spar, maybe have a coule of maps, you both warp to, that have buildings and are a decent size for a building or two, i find it better than a small arena around you, i think it woukd be easier that way! Cause what if its in start, and a couple arenas are around you when you need to get to a certain place and such. Maybe just a highlighted area that if you leave, you lose. But players cant kill you, only ypur opponent. Maybe better than a whole barrel thing, and easier!