I would stay away from prong collars. They have their place in training, but for a dog you haven't tried anything else with... Why make them your first choice? You could use loose-leash training as an opportunity to really bond with your dog and create a great team-work based relationship. Look into other options first!
I love this method and recommend you give the video a watch. This method will help the dog learn to associate you with good things, and your dog doesn't need to be administered discomfort/pain. Additionally, I know sometimes dogs learn not to pull on the prong collar but as soon as it is removed they go back to their old habits. Instead of teaching your dog that not heeling is painful, let's teach him heeling is FUN
Link:
http://www.youtube.com/watch?v=rRZa5o2_6eo&feature=plcp