Looking for simplistic internal proxy software solution for proxy farm

Hello All. I was looking into proxidize and proxysmart. However I now realized that I can really use something much simpler seeing as I do not plan on renting these out or selling the services - I use these in house. All I need is some way to send a signal to the modem/USB Modem to rotate the IP. Is there a modem that allows that to be easily done via command or API?