I've had several ercp's the first 2 I had general anesthesia and the 3rd one I was just sedated. Trust me you want the general. The ercp is much more invasive than just and egd.
Don't even THINK about having an ERCP without sedation. The entire procedure is longer because the doc has to go beyond your stomach and into the duodenum to locate the opening of the common bile duct. Then dye is run up the duct so it can be visualized under fluoroscopy. It does take longer than a typical EGD. If any doctor tells you that you can do this without sedation, I would advise you to run, and find another doctor.
I had ERCP several years ago, and the sedation needed was a bit more than EGD according to the anesthesiologist. In my case, they started with versed and demorol, and then to thorazine because I started to wake up. I have a very vague memory of that and it was only for a few seconds.