It'll perch on the coral w/no problem. Also on the front glass, powerheads, rocks, whatever. And yes he will swim to the top for food like the others.
2 might fight if not mated. Consider a bi-color blenny for the 2nd fish maybe. Again, great personality. The bi-color will find a rock to stick his body into and let his head peer out. Really neat fish. And both of these choices are small - maybe 2" max for the blenny. Maybe 1.5" for the goby.
BTW, how are your nitrates? That'll tell you IMO
if you should add 1, 2, or no fish.