One thing in general I'll say - there is a lot of talk in here about dive operations, pros and cons about this one or that one, and I'll just point out that the reefs are the same no matter who you go out with. Some ops may get you there faster, some may be more crowded, and, yes, some offer bigger tanks if that makes a diff to you, but the reefs are the same, and the diving, once you get in the water, is up to the diver.
Can the dive op put you on the reef? They all can virtually 100% of the time. The rest of it is mostly small stuff.