Pizza ovens are kind of simple, you can follow a design for those, smokers are the hard thing, The first one I built was terrible, I learned a lot replacing this and that till it worked, problem is there are no real resources to look things up and most of the plans are not that great. You need a good firebox, and that is a thing in itself, that firebox is going to be a thing you want to not only deliver heat and smoke from, but also be easy to maintain and easy to use. you will be making a fire, keeping that fire at a certain level, maintaining flavor wood in it, releasing said heat and smoke to the smoker part evenly, and, you will need to be able to clean it up easily. The smoke box is repetitively easy from there, the only concerns are how big, layout for such as sausages et al. making it a smoke box and not an oven and if you want it to be a smoke box/charcoal grill. That is a nice feature in itself as now when not smoking stuff you can use it to Grill. A line up of oven , gas grill with 2 side burners, smoker/charcoal grill and sink with running water is my dream and will be built when I retire and move back to Florida.