PIC Controller

I have a project that I am getting started, and I am going to need a PIC controller that can control a stepper motor and be fed info from usb.

I Have a device that gets plugged in via usb. I want to put a pass thought usb plug between the device and where it gets plugged in so that the pic controller can read when the device is turned on and when the device is turned off. In both cases I want the controller to run the motor.

What are my options. Where can I find a controller that will meet my needs. Any input is much appreciated.