I'm sick of not being able to put any of these cool non-reef compatible fish in my reef tank. So I'm thinking of converting my 46G bowfront african cichlid tank to a FO saltwater tank. my current setup is:

tank: 46G bowfront
lighting: 36" florescent 50/50 GE aquarays
substrate: 2-3" coarse aragonite
rocks: slate and limestone
filter: 2 x 330 pingui bio-wheel each rated for up to 55G

I'm thinking my filtration is probably fine for FO. Ideally I would like to run a wet/dry, but this tank is sitting on a ledge in front of my fire place, so there is no cabinet to put the wet/dry in. The substrate is also fine (might mix it with another 2" of southdown), but the rocks I will have to replace with live rock. The lighting might also be fine since I don't plan to keep any corals in there, but will it be enough for coraline algae?

How many fish will I be able to keep there and still do a once a month water change? I was thinking of a humo or clown trigger, dwarf lion fish and an angel or a butterfly?

Any thoughts or ideas on the setup or the livestock?