You're probably gonna need to get 2 more bulbs to keep SPS
anywhere besides the very top. Also more flow will probably be needed if this is going to be SPS
For positioning you'll want to go for a more chaotic flow, your's seems pretty circular from the picture.
As this has already been addressed I'll just give a bit more info. The tang needs swimming room, not necessarily about it's size in this case. Even a small tang could and will get stressed and possibly injured in a tank your size already. I suggest moving him out and getting something else, disaster can happen very fast