What do you require to start a proxy website other than a script? Do you need to get a proxy ip from where?
Well, the server the Proxy Script is hosted on acts as the IP address the Proxy Script will work from.
Dude Don't go with proxy sites... take this as a suggestion... you wont be making good ad revenue from it.. since google has taken notice of proxy sites and basically there are too many proxy sites out there.. but for your question you just need a script a shared hosting for begining and if its getting heavy switch to a vps or a dedicated(recommended)