Many pseudoanthias species stay quite small, 3 inches or so. These can quite easily be accommodated in a 60 gallon tank. Though they are tough on the filtration, as already noted, because they do need multiple daily feedings (and will often not take pallets or flake foods). The larger species need more space.
I've kept princess, resplendants, randalls, carberryi, igniitus, and probably a few others I'm forgetting in smaller tanks. Lyretails, bimacs, Bartletts and squares grow larger and I always kept them in 180 plus gallon tanks.