Set-up a proxy server

We're currently renting HTTP proxies from multiple websites, but they do not have a 99% uptime. I need someone to set-up a VPS for me for the use of multiple HTTP proxies. I will buy a (dedicated) server, and the needed IP-address. You need to do the set-up and tell me how to maintain everything. I am experienced in Linux, and have set-up multiple VPS for different purposes but never for the use of HTTP proxies.