How do I make Safari, Chrome, Mail, and other applications all use different SOCKS proxies

How do I make different applications like Safari, Chrome, and Mail all use different SOCKS proxies. FireFox has it's own proxy settings, but Safari, Chrome, and presumably Mail all use the system proxy settings. I need them to all use different SOCKS proxies, all running simultaneously under the same user and login. I have all the SOCKS proxies set up on different ports already, each is proxies into a different company in a different country using ssh -D.