USB Motor Controller

I want to control speed of DC motor with usb. from google i found that i can use 18f4550/18f2550 to communicate with usb port and create pwm output from ccp pin.
i'm new with pic programming, still a lot to learn.
which one should i use, cdc or hid. i want use vb to control the speed of motor, and i want to get feedback of actual speed of motor(by count pulse from speed encoder).
Please help me.
and sorry for my bad english :)

PIC 18F2331 has feedback input and 8 power control pwm. This is suitable to your need.
As for usb connection to VB, just use normal usb to serial cable. This way you do not need to learn usb .