The problem is with this suggestion is that if you have a arena for pvp that is good for you but we arent able to make it pvp enabled for you. If it was given to you then others would want it. Mr naithantu i believe is still looking for pvp maps but for arena's im not entirely sure.
There is only 1 pvp arena in the regular survival world that is in the staff city. The others being in the pvp world. If pvp arena's were given out to all players it would degrade the server in a way that shows sloppiness given pvp arena's in all worlds and everywhere.