You could do that but I would personally would get another golden zebra, they would probably prefer their own species. Just to clarify, we are talking about botia histronica (Golden Zebra) and botia striata (Zebra)? I have my striata with almorhae (Yoyo loach) and they get along just fine. But I have 6 zebra, and only 2 yoyo, wanting to get more though but they are a bit hard to come by down this way.
Substrate sounds fine, I have the small rounded gravel too and no problems.
Mine like the shrimp pellets too. Do you have any blood worm? Try some of that.