Need Giveaway Site Script/Ideas

So I am creating a website with giveaways for stuff like games, software, electronics, etc. The site will be completely legit...I really will be giving away what I say I am. No bullshit. Now I know I want to lock the content somehow so the users have to fill out a survey and then can enter there name into the drawing. I don't want anything like sign up for credit cards or any of that crap. Free offers that earn me money. Are there any good themes/scripts for this purpose that you guys would recommend? Also, any good survey networks to work with?