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Echo everyone on the boston butt suggestion. You can buy it either with or without the bone as the bone slides right out when the thing is done, and can be (at times) a little cheaper.
You want the fattest (biggest) picnic shoulder of the hog. It may be called the boston butt in Yankee places, but it's a "pork picnic" in the South. No worries, just get a big one. Cook it real low (225-275 max peaks) over good heat. Got to get a good rub on it initially, and you gotta get a good sauce to end it with. You have the Carolina western sticky sweet sauces, and the eastern vinegar based sauces which are not so sweet. Send me a message if you want details or a recipe. Best to you!
Either or are good, You can also find Cushion meat at Sam's Club. It is boneless shoulder and they are smaller for a quick smoke. I haven't tried them yet, but that is my next smoke.