Acanthurus sp. are the harder species to care for whether just hard to care for period like the Achilles or extremely agressive like the Sohal or Clown. One of the easier to care of is definately from the Zebrosma(sp?) sp like yellow, scopas, sailfin, or purple(even though they are pretty aggressive in their own right). Oh yea and the unicornis sp, the Naso and Unicorn or Vlaminigi tang are easy just need proper tank size 125 gallon minimum tank size and good water conditions.
Melly