I do have worldedit if you want to build it in single player or something then import the "Main Base Station." I think that'd be best so it doesn't interfere with member's activity until it's ready.
A more advanced minecart system. Preferably one that can handle multiple carts going one way, and multiple going the other way. with 'stations' to different areas like the spleef area, mob arena (being set up), and more to come in the future.