The Su-7 - in 1/48 scale - has one kit in town: the late 80s kit from Kopro/OEZ recently re-boxed by Eduard. The model is somewhat limited in surface detail and different manufactures offer ways to enhance it. Among them is Master Model which offers a drop-in replacement for the guns and pitot tubes (nose and wing).
As you can see in the pictures, the guns are a vast improvement over the originals, which are basically a plastic rod. The metal replacement parts have nice hollow ends and have different lengths to properly reproduce the placement of the guns in the Su-7.
The wing’s pitot tube has a much fine shape than the plastic one. Please note that you will have to keep the base of the plastic pitot tube and modify it to receive the turned brass one. Very simple to do with a file and a drill bit.