The Boston Butt is a lot easier to find at a typical grocery store. However, I would suggest calling in a order a few days in advance and get one cut at 7-8 lbs. I have found that these will still have the bone and a decent amount of marbled fat. Ask for one over this size, and you end up with a fat cap that you should cut away to about 0.25 inch thickness. If you don't cut it down, it is just more to toss after the butt is pulled. Regardless, you are still paying for too much fat with a "oversized" butt.
Speaking of fat, a typical picnic will have a noticeable fat cap. I find that the pick nick reminds me more of ham than the butt does. Also I have found more bones in the pick nick, for a notable larger net loss in before and after weight for a pick nick as compared to a butt.
I have converted many a person to slo-n-lo BBQ, via the pulled butt. Folks show up for the ribs, but the butt is something that few have had and less can properly cook. Like brisket, slo-n-lo is the key. I have found that mops are not really needed with the water pan, but to each his own. The other great thing about the butt, is that you can pull it, and place it into small freezer bags. It stored well, and this smaller quantity is great to share with friends and family. Any more, I have to smoke 2 butts to keep people supplies with to-go packages after dinner, and still have enough for a few days of sandwiches!
Ted "slo-n-lo" Former