When you add a fish, it is nice to couple beauty with some useful aquarium function. I had a Yellow Coris Wrasse for several years till he took the great leap, and that fish was a worker! Ate any and every kind of pest you would ever want out of your tank. Lots of fun watching him eat bristle worms and trying to get the stickers out of his mouth. He used to grab stomatella snails by the half shell and hit them on a rock to loosen the shell. Poor little naked snail fish food. Flatworms or anything else that comes in by accident were taken care of quickly without any chemicals. I've always loved a yellow headed or blue spotted jawfish as well - you get blue and yellow!
I think if you have a fish eater with the sally lightfoot, I think you have a decision to make as it will likely keep catching what it can. My personal favorite yellow fish is the yellow fang blenny/canary blenny.
BTW- This is the exact type of question the Fish Finder is supposed to help us with. We just need to get more members to input their fish to make it a useful resource.
If you have too small of a tank for a yellow tang, I would go with a Midas Blenny, they are VERY cool to watch and not as "hiding" as other blennys they hang out in the open swimming around, very active.
I love the Midas blennies, just figured they looked like the next best thing for whatever et the other two. And being even more pricey than the canaries, I am a little fearful.