I've been asked to create/shoot a max headroom type video live for a corporate event. I need to use a green screen for the floating head and was wondering if there is a low cost piece of hardware i can purchase to key out the green screen live? Any ideas? I will only be using this once so don't really want to drop a lot of $$ on it. Also if this same piece of gear can do any effects(cheesy) would be cool too.