Kyle, whole (or "packer" cut) briskets are best. These include the flat and the point (the 2 muscles that make it a packer). You'll be hard-pressed to find a packer less than 13-14 lbs, so don't worry about the amount per person calculation. For 10 people, I wouldn't go less than 14 lbs, as you will trim about a pound of fat off of it, and it will shrink. Besides, who doesn't like leftover brisket?
The trimming video is good, but he trims way more than I do. He almost completely separated the point and the flat, which I don't do until it's done cooking. I keep at least 1/4" of the fat cap on the back of the flat, and then score it in about 1" squares, rather than create the "pockets" like that guy talked about. I, like the guy in the video, do remove the heavy, dense fat around the edges.
At 225, I always average 1 - 1/25 hours/lb, on brisket. You want 6-7 oz of hickory, for the wood. "How many chunks" is a question I can't answer, as it depends on the size of your chunks. If you don't have a cheap digital scale, I really recommend getting one to weigh your wood.
When you go to RD, buy at least a USDA Choice brisket. If they have USDA Prime, get it; brisket is one cut where the extra $ for Prime is worth it, imo.
As for rub, I've never used FD's Rib Rub on a brisket. While it is fantastic on pork, I don't think I'd be happy with the flavor profile on beef. Brisket needs salt, black pepper, garlic and onion. Bold, and simple. I use a seasoning called Jim Baldridge's Secret Seasoning, but you have to order it from the small company in Nebraska. It's killer on beef. I wouldn't use FD Rib Rub because of the sugar and paprika...just not my cup of tea, on beef.
