The technique is best done with high-quality optics because they have better coated glasses which help increase clarity and reduce light loss. However, just about any scope and digital camera will work for at least identification/proof shots, so long as the camera’s lens size matches as close as possible to that of the scope’s eyepiece.
Digiscoping requires a lot of practice and to get high quality shots, it is best to use a setup that is designed for this technique. Optics companies often sell adapters specifically for attaching the camera to the scope. Swarovski makes such an adapter that works perfect with just about any camera and their awesome spotting scopes.