The simplest solution may be for you to get a router to let it be the gateway for your PS3. With your ISP using the filtering this would be the easiest way to trick them. This could be done by changing the MAC Address of the router to the one used by your computer (very easy to do) and everything going through the router would look as if the ID is your computer.
I would recommend either a Linksys or D-Link brand router.