protein skimmers can hang on the back. fluval is good for moving water but your main filter will be live rock and ideally youll want to have 200 or so lbs of it for your tank. what i did was bought like 1/3 live rock and 2/3 base rock and let the live stuff move onto the nonlive. i left the light on longer and dropped a few prawns in to decay and eventually all the rock had nice purple algae on it as wel as some microorganisms so i didnt pay a ton of money for the rock.
as far as stocking it, you could do bigger fish like a volitan lion, picasso trigger, snowflake eel, and maybe a puffer. or you could get just one beast fish like a panther grouper, a huge angel, or a small shark.
as far as smaller fish go, clowns (preferable a proven pair), dwarf angels (one per tank), small hawkfish, bangai cardinals, gobies/blennys, jawfish, dwarf lions, valentini puffers, small wrasses, and others are all game. not that they can all go together but see what you want for sure and we can let you know which fish can do alright with it. good luck man.