So here I made my own version of the arena from PopularMMO's and I hope Pat and Jen like it.

Only truly required mod: Lucky Block Mod

While you can use this in vanilla you will lose some chest stuff including lucky blocks. So make sure at least have Luckyblocks version 5.1.0 or higher installed. If you want to play this on Multiplayer server then make sure commandblocks are enabled. The arena currently supports 12 players, lucky block-wise.

Reason why I can't use MCEdit Schematic:
1. My mac won't work MCEdit due to code problems (This has been fixed)
2. Several command blocks rely on exact coordinates.
3. Further upgrades for this arena will be no longer in effect as of the 1.8 version update.

For the 1.8 version see here: http://www.planetminecraft.com/project/popularmmos-arena-18-version/