Nice looking rig, solid & no skimping on the firebox. For your RF plate, I just had the metal shop cut me several 1/4"x6" plates. For RF, I put them in tight against the firebox opening and each other leaving about 6"-12" open at the end opposite the firebox. Or you can space them out a little and they will act more like a baffel plate. very versatile.
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.