if you get a samll one 3" or smaller it should be fine in the tank for at least 2 years. ive had minbe in a 90 gal for a year and he has only grown from 3" to less than 5". he will be moving to a larger tank in less than a year, so i think he will be ok until then. his favorite food is red macro algea.
I have a 7" Naso in a 125,He has been here for 7 years.This guy is a pig,Feed them anything frozen.They love lettuce and Spirulina flakes.They are great fish and very easy to care for.Make sure you have a good filter because he will make a mess.