Sohal tangs are easier to keep than clowns. Clowns don’t ship as well, are susceptible to a lot of diseases, and having a high flow, oxygen rich environment is almost necessary. Every instance of long term success that I’ve seen with them involves a wave maker of some sort. If you’ve had success with them without the wave maker that’s great. They’re also two of the most aggressive tangs. If you decide on either, I’d add it last/add it with all other tangs at the same time, and get one that’s smaller than the other tangs in the tank.
As for the future stock list, majestics are one of the most passive large angelfish in my experience. If you want a more aggressive Pomacanthus angelfish, an Emperor or French angel would be able to hold their own better. I’ve done it plenty of times, but it’s always risky mixing angels, especially Holacanthus angels like the Passer and Queen. That genus is one of the most aggressive compared to other genus of angelfish. The stock list would probably work in an 800 gallon, but some of the fish, like the Passer, Clown/Sohal, and Miniatas tend to be some of the most aggressive species in their respective classifications. Just something to consider when stocking the tank.