no simple answear to the question sorry! it depends what you want to so with your tank in the long run. if you want a full on reef tank with hard to keep corals and all that you want less fish then if you were only doing a simi-reef and for that you would have less fish then if you planned on doing a FO tank. the trick is the more fish you put in your tank the bigger the bioload is meaning the more water changes you will have to do you will also have to test the water more to make sure everything is right.
as for your inverts they don't count. because they are part of your clean up crew meaning they take out more or the same amount as they put into the water.
just remember the more fish in your tank the larger your bio-load meaning the more water changes need to be done, also useing a protein skimmer is a good idea.