Build plans for new smoker

I am not new to smoking meat and have had numerous smokers over the last 20 years. I am planning a build of a healthy size smoker. I am curious for discussion purposes the terminology of some parts of a smoker that are used here.
Everyone knows what a fire box is, and there are a number of types of cooking chambers. I am curios what you are calling the upright type of cooking/holdover box that is some times propane heated? like the one at the end of this one in the picture.


Also do you typically cook in this vessel or is it for hold over?

I like elements of that design, I will use a square fire box a pipe for the center cooking area and then build a rectangular verticle box at the opposite end of the fire box.