Welcome to the club
@Jdc !!
If you are specifically asking about brisket, I'd suggest the Master Touch. A full packer brisket isn't too difficult to do on a 22, no accessories or modifications needed. An 18 can do a lot of things, but a whole brisket might be a bit challenging, without accessories or modifications.
I did this 12.35lb whole brisket on a Jumbo Joe, with Cajun Bandit Stacker. I put a bowl under the brisket, when I first put it on the cooker, to get it to fit. After shrunk up a bit, I removed the bowl for the remainder of the cook.
This last picture shows a whole brisket on a 22, without any modifications. There are two fire bricks in the foil, but those are not necessary.