I have a 40b with a 20 gal sump and have 9 fish in addition to my CUC and corals. FYI if you have a 40b it's not 40 gals, it's 47.5 gals.
Fish that I have are
Cherub Angelfish
McCosker's wrasse
Royal Gramma
Pair Mocha Ocellaris clowns
Midas Blenny
Yellow Candy Hogfish
Scooter blenny
Matted Filefish
All get along pretty well with very little fighting with the exception of the Cherub Angelfish, he's my "terrorist" fish. Nothing bad just chasing mostly.
I also suggest to buy only Scarlet Legged Hermits, they will not kill anything, where other hermits will, especially snails for their shells. The Scarlet Legged hermit is an honest worker and does a great job. Snails are good to have a few different kinds. Nassarius snails for the sand, Astrea, One or two Mexican Turbo's, and Stomatella snails. There are others that are good but these are my pick. I've also got hundreds of brittle starfish and more asterina stars than I care to count

They do keep the tank clean though.
Some will say that my tank is overstocked with fish, but I judge it by two things. Fish behavior, and nitrates. You need a good export system for nitrates/phosphates to have it work. A good skimmer as well as chaeto or other algae growing in your sump.
Yes Live Aquaria is a great place to find out basic info on fish you want. I highly recommend any of the fish that I have in my tank. Yes you'll love the Midas Blenny.
So pick a list of fish you want to have and post it up so we can let you know if certain fish are ok together or not.
Just remember to go SLOWLY adding livestock. Otherwise you'll get an ammonia spike and possibly kill your tank.