generally speaking, people recommend-
23g, 1 1/2 inch for glutes
25G 1 inch for quads and delts
I am in the midst of my first cycle, and just an FYI- I was planning on doing only glute injections for the whole duration, but some knowledgable people on here said thats not a good idea. Not sure if that was what you were planning, maybe i misinterpreted