On the question of zooms and primes, don't forget it is position that creates perspective NOT focal length, stand in the same place with a 24 as a 135 and crop the 24mm image and you get the same portrait, all be it with greater dof.
Bearing that in mind, and the fact that end use is unlikely to go very large or high quality, then the 24 would give me the most flexibility. Shoot to crop and you won't go wrong, try to fill the frame every shot and it will be very formulaic.
I agree that shooting to crop is the way to go, but not a extreme amount. You also get exposure issues when you are too wide, the subject tends to get a wrong exposure, so you have to be very careful and use exposure compensation or preferably full manual. When colored lights are constantly changing, it is even more to worry about.
I usually have a lot of working room, from 5 ft to 60 ft, so I can use 35mm or even 24mm by moving around. I can also get different angles. My 85 or 135 is my usual choice, but I use them all. If a person is seated at random in a club, there is no telling how far or close he will be, and if light is low, a fast zoom or prime is the choice. I've never been happy with my 24-105 in low light at f/4.
The 5D3 lets me crop a large amount if I have to, but I prefer to crop just a little. If I was 8-10 ft from a performer, I could use 35mm, but 20 ft, I'd prefer a longer focal length. If I want a 1/2 body closeup shot, 24mm is too wide.
The OP should take all three of his lenses and see what works for him.
135mmL back about 6 rows from the stage
