hey rory.ive got a 2ft tank and have glowlights,neons,black neons,black widow tetras,zebra danios,serpaes,diamond tetras and kuhli loaches.i definately recommend kuhli loaches as they are really cool and do a good job at cleaning the bottom of my tank ie. leftover fish food and they dont grow that big and get on fine with my pleco.glowlights,neons and black neons are cheap and cool andwould go well with your black gravel.im not sure about fighters tho.good luck with the fish selections.