Even with just a few revolvers, you will need more than four screwdrivers. I have a Wheeler Engineering 80 piece set and I am satisfied with it. This set includes a rebound spring tool which I do find useful for removing rebound springs. I prefer a screwdriver for installing rebound springs.

Even with more than 60 screwdriver tips, I recently had to grind down a screwdriver to a get a satisfactory fit in a revolver screw. I forget which revolver, but it was not especially old or unusual. If you have a variety of revolvers, you will find a wide range of screws.

My Wheeler Engineering kit is about 10 years old, and I am satisfied with it. I have heard reports that their quality has gone down, but I do not have direct knowledge about that. I only hear high praise for the Brownell's screwdrivers, but they cost more money.

Also, if you are interested in revolvers, I recommend Jerry Miculek's Trigger Job video. I recommend this video even if you do not want to do trigger jobs. This video is one of the best gunsmithing videos that I have seen. It provides a detailed explanation of assembly, disassembly and parts function. And it tells you a lot about how Jerry thinks about revolvers. The Kuhnhausen books are an important technical resource, but they are not an introductory text.

Note that Jerry has another video on assembly and disassembly. Those subjects are well covered in the trigger job video, so I don't think that a video on assembly is necessary.