HI,
Naso's are part of the tang family that will greatly appreciate a larger tank when fully grown. The 125 would be OK for a sub adult but naso's get larger than some of their counter parts. Other tangs will be perfect....yellows, regals, koles, etc. also no vlamingi's they are a large tang also. But IMO I think itll be fine for a Naso. Naso's are also considered hardier than some of the other tangs available.
Chris