DOWNLOAD (for Doom 1)
Here's the shader + a bunch of normal maps already done for The Ultimate Doom! OpenGL 2 cards work just fine with the shader (performance may vary, but generally speaking if you can run Doom 3 decently enough this will run fine too).
The normal mapping is completely based around dynamic lights, so no dumb "just works with 4 lights pre-set in the shader", it works very similarly to GZDoom. Only floors and ceilings are normal mapped, while support for walls is there, it's very inefficient (not like it can be improved much) and only supports 90-degree walls correctly, so I've disabled it.
If you think the effects are a little too subtle, you can go into Options > Display Options > OpenGL options > Dynamic Lights and increase the light size there. I did this for the screenshot with the 3 torches, so the light would reach the ceiling better.
Spoiler: Screenshots (Open)