Welcome to the board
1 inch per gallon?, well maybe 1" per 5 gallons is more like it. with regards to fish. Some will say 1 invert per gallon, but I think you can at least cut that in half say 1 per 2 gallons.
It depends on what kind of system you like, fish only, fish with live rock or Reef with corals.
If a reef tank then many of us prefer to keep the fish bio load low and concentrate on corals and coral bio load. With less fish per gallon (so to speak) you can better control your water paramiters.
As far as inverts (cleanup crew) they are a very small part of a bio load. That is sometimes said to be 1 per gallon. As far as purchasing a reef package, I always like to pick and choose what I add, this will also depend on how much live rock you have. With 10 pounds of live rock it wouldn't do you any good to have say 50 hermit crabs in a 55. Now if you had say 50 pounds I might have 15 - 20 hermits and 20 different snails.
Let us know what type of system you want, how much live rock you will have, perhaps even what type of filtration and what substrate you are thinking about.
Thomas
