If it's all the same with you, Tri, I'd prefer a server that doesn't have all that stupid stuff and just focuses on playing Minecraft.
This would be implemented using multiverse, so the arena would be in a different world. Survival would still be the main game here.
And the economy would really be just for shops, and for trading, but if you guys really don't want it, that's fine. Rewards for rounds in the mob arena would be items I think.