You mean you want to use the PS3 controller with the USB cable attached? If you succeeded in using the controller wirelessly, you should be able to use it with the USB cable attached as well.
Here's an idea: You can pick up brand-new genuine PS2 controllers for $20. Adapters cost $3 or so (just make sure to get one for the PS2, not PS1, because of the pressure sensitive buttons).
Which gives you a wired controller akin to the PS3 one, minus the gyroscope, but chances are that you won't use that anyways.