I have an older Canon 5Dmkii, and it has a dial for shutter speed near the shutter release and also has a dial ring for aperture control on the back. I'm pretty sure the mkiii and mkiv do as well. I know the 1D I used in the past also had the same configuration of dials.

As with anything camera related, where to buy could be B&H, Adorama, Sammy's, or your local camera shop (if they still exist in your area).