Whew. it does sound like this might be a bit much for a first project... It's not insanely complex, but coming in to it cold might be a bit much.
I am actually going to be building a panbot at some point, you can actually get away with a lot simpler and cheaper that the device shown. The biggest item is simply that he's running two axises. For most panning, horizontal pan is sufficient and can be done easily with a standard stepper motor or even a servo. Working against gravity is tough, rotating a balanced load isn't.
The isolator is connected so the output serves as the switch for remote shutter release, most slrs have a 2.5mm jack.. Complete the circuit, it is the same as depressing shutter button.
The panbot is as simple as rotate, stop, release shutter, repeat.