I have a Weber Smoky Mountain, which is a vertical, or bullet-style smoker, which I’ve been very happy with. But if you plan to do a lot of whole briskets, a rectangular model like a Camp Chef Woodwind Pro may be best.
What I was going to say-- Keep the Weber grills! They’re two different tools for two different uses. Except, a Weber kettle grill can do some fine smoking as well. I’ve cooked whole briskets on a kettle grill using an America’s Test Kitchen method, and every time it came out magnificent.