I purchased a rock climbers harness off from ebay... a pretty spendy rig I got used for $200. It retailed for $450 and came with a bunch of clips and extras. And it had nice shoulder pads. The bungee cords I used were also from ebay. I got 7/8 inch marine bungee cord. It was strong enough that I only had to use two strands of it for a 145lb actor and it had plenty of spring to bounce the actor right back onto the platform. Of course it came in 50 foot length so I have enough for a long while but thats ok as I figure I saved a ton in the long run anyway. We strung a cable between two trees and clipped the cord to it. You have to get whatever you are attaching the bungee to pretty taunt so you dont loose any spring. There was a thread on here about the bungee platform and we used that to model our platform off from. Next year we are going to modify it a bit. We are going to make the platform look like a hangman's gallows and the actor will be standing on a plexiglas stand so he looks like he is actually hanging in the air. then he can launch from there. I thought of it while watching him jump at people this year.... mind is always working!