OK first off. Fish Only I really wouldnt recommend doing a
FO because you take away your number 1 filter your
LR. You will have to have a nice clean up crew and will have keep up on your
pwc and filter cleanings as you cannot have things getting dirty because just a filter in my opinion will not be able to handle such a bioload. Second a
FOWLR. They are nice if you are looking for your more aggressive fish or cannot handle the Reef setup yet. The
LR for one acts are your natural filter I have 100+ lbs in my 55, second it give all types of life ample hiding spots. As for the Reef setup which can be intimidating at first but rewarding down the road is the reason I got into saltwater. You will need a lot of
LR for this along with a higher salinity. Very High Lighting I have 492Watts
MH /
PC Fixture for my 55. A lot of coral need this high lighting because they host a symbiotic relationship with Zooxanthellae. Zooxanthellae, a strain of single celled algae(they are dinoflagellates, photosynthetic protists considered to be algae. they are photosynthetic and produce energy for the coral. Once you have done a lot or reading and maybe ran a
FOWLR for a while i would definently start a Reef they are wonderful. One little point GO SLOW.
HTH