This should be in the native section, maybe a mod could move it?
Anyway tank envy :env:
With a tank that size I think it would be much more dramatic and interesting to go full out with kokopu, inanga and bullies e.t.c... (if you can keep it cold)
But if you went with the boring option ( ) you could probably have 20-30 bullies (I think) just make sure there are lots of hiding places (bullies are active but as they get bigger and more territorial they need their space....)
Also if you take a large number of natives take small numbers of young specimens from multiple healthy populations.....
And large numbers of natives (as with all fish) need large amounts of food, so make sure you can keep up with their intake.
Hope I helped, have fun.