A small amount of ammonia detoxifier would be good. Be careful as some types remove o2 from the water as they work, which is a big issue when shipping fish. Some use bag buddies, or a product called ship-shape that contains a mild tranquilizer that will calm the fish to slow respiration during the shipping process.
Toward the end of my cichlid breeding days, I also experimented with the kordon brand "breather bags" They work extremely well. I would recommend consulting google and get some info about them. In certain situations they work rather well.