I have (2) B/W Clowns, purple firefish, midas blenny, pink spot watchman goby, cleaner shrimp, (2) emerald crabs, serpent starfish plus tons of corals.
To answer your question about stock, you already have (8) fish. I would think you are fully stocked. A lot depends on the swimming behavior, size (of course), bioload, personality, etc.
I have the (5) fish in mine, and I feel like I'm stocked. I added a small sixline wrasse, didn't make it, but I felt it was just too much for my tank.