Very kool build! I like using what you got and your ideas should make a pretty functional vertical. I also really like those 1/2 split firebricks, used them to line my firebox and they work great.
The first smoker I remember having was an old porcelain steel insulated fridge with a charcoal habatchi in the bottom, very small fire and vent holes in the top & bottom courtesy of a sledge & big screwdriver, just kept punching holes until we got it working. Made some good mullet & mackerel with that one!
Weber 26.75 OTG w/CI grates & SJ/WSM Mini
Home built 24"x72" reverse flow stick burner trailer with 18"x44" grill w/CI grates and upright SS gas oven/smoker.
Home built 48" fire pit with a 30"x30" Santa Maria style ranch grill.
Home built lump charcoal retort, iGrill & a bunch of other cooking toys.