There are 3 main drill types that can used for bolting routes, hand, electric or petrol drills. (Note: The bolt gun used in Cliffhanger doesn't exist, considering the force needed would probably take off your hand.) I recommend petrol drills if you can afford one, the main reason being the ease of use. Petrol drills will generally drill more holes before requiring refueling, which is easy, and normally have a lot more torque. They are however very noisy, sounds like a chain saw, and very expensive, (The one shown below cost $800), and are hard to find. I went to heaps of hardware stores with no luck and finally managed to find mine at a lawn mower shop.
The problem with electric drills is that they lose torque as the battery goes dead and unless you have a huge supply of battery's it can be a problem. They do cost a lot less, are lighter and easier to find. Hand drills are hard work and for any serious bolting I wouldn't recommend them.
One thing to keep in mind regarding drills, is you have to take them on rope with you to bolt. With our drill, (as seen in the pictures), it has a handle to attach a tape to, which we attach to our harness. It hangs underneath and is out of the way until needed. Its no use having a drill you have to carry as you'll find doing rope work hard with one hand.
The drill pictured belowt is an Echo