Yellow and naso would work if you have a big enough tank for a naso to begin with, they are different body shapes and nasos tend to be less aggressive, they just get over a foot in length so 200 gallon+ would be recommended, scopas and yellow will not work most likely, very similar and very aggessive. I wouldn't risk it.
Actually looking at your profile, I wouldn't suggest you add anything to your tank until you upgrade to a 90 gallon or more, your eel and tang need way more room to be healthy and that much bioload in a smaller tank is asking for disaster, they are both huge waste producers. I would take them both back and buy fish suitable for your tank size until if and when you are able to upgrade.