Your tank is large enough to accommodate several tangs.
But, from personal experience I would ask that you seriously reconsider the orange shoulder tang for a couple of reasons.
If you intend to keep several tangs, there are much more beautiful tangs available than the orange. Although cute when small, they grow quickly and become rather drab looking when mature.
As the mature they become very aggressive prohibiting you from adding further tangs later.
They are very active like sohols and prohibit you from adding peaceful type non-tang species.
If you like tangs take the time to study all the species.
Here is a listing of the bad ones with reasons why
http://wetwebmedia.com/badacanthurusaq.htm