Add double elimination to tournament script

Our tournament site currently only has single elimination tournaments. We would like to add the feature of double elimination with the ability to set either single or double elimination when creating a tournament. We also want to add the ability for members to challenge each other for cash. i.e., member 1 challenges member 2 to a Counter-Strike match for $10. Member 2 accepts the challenge. Both teams must then put $10 into an escrow account. Once the match has been played we receive a percentage and the rest is released to the winner.