i wouldn't suggest powder blue or achilles tbh...
if you're looking for an easy tang to care for that is..
go with a sailfin, yellow, hippo (or yellow belly), kole, or a naso.
IMO those are some of the easiest tangs to care for.
on the other hand..if you really want to shell out the dough for it..
go for a black long nose ^_^ but you won't find them for anything cheaper than 295.
they look just like a yellow tang with a slightly longer snout and they're all black --> very hardy fish might I add and not as aggressive as a purple.
just remember, don't mix same body types becuase if you do, even the least aggressive tangs will become cereal killers.
good luck!