There are some other type of tangs that could work in your tank, just tell him it's Dory's brother. Lol
blue reef chromis are beautiful, you could get a small school of them. There are some gorgeous SW
fish, go to liveaquaria.com and show him some pictures of some fish after you've researched which ones will work in your tank. Personally, I only go with fish that say "peaceful" about their temperament Because I don't want any killing or bullying in my tank, but some people love the predators. To each his own, I guess. Have fun looking at all the pretty fish!!