I worked at an MMA gym for about a year that just shut down yesterday... One of the business partners pulled out, and the other guy didn't want to run it on his own.
I would say that having rigid class times and a reliable class structure are HUGE, maybe some of the most important things. I've trained off-and-on at a bunch of gyms, and that always seems to separate the great from the mediocre. I've seen moderately-talented instructors run great schools because the environment was set up so well for learning.
Weights-wise, it's hard to market traditional weights in the martial arts world, although it's catching on now. Bumper plates, a platform, and a 20kg bar are by far the best pieces of equipment you can have, but you'll have a hell of a time trying to get most people to do Olympic-style lifts. Kettlebells are a good substitute.