Larger. Despite being slow growers, they will reach 10" SL. Four 10" fish is a bit much for a 40br (though they can stay in one for a long while). I like 125 gallon min. for the larger Satanoperca species, but if you kept up on the wc's a 90 should work. Also I'd do at least 5, that is the smallest number group they are found in the wild.