Gas Power auger recommendations

Well, if it were me and I was doing a panel section at a time and was in no hurry I would use good ole post hole diggers. You would only be doing two to three holes at a time, right? How tough is the ground there? Also once you pull the post out part of the work is done for you.

I did a fence here with, whew, probably 40 posts and did it by hand. It took me a week though.