I'm setting up my first marine tank at the moment and would like some advice on what fish to get! It's 4ft long 15" wide and 18" tall, around 40 gal (182 L) excluding the volume of the sump, I have no idea what fish or coral I could have living together happily in there! Or how many fish is too many in a tank of that size, any help & advice is much appreciated, cheers