Swallowtail Zebra Angels

[Sac1]

I have a 250 gallon reef that is about a year and a half established. I have a chocolate and a lavender tang, a magnificent foxface, a pyramidal butterfly, and 2 female swallowtail zebra angelfish.
I am only planning on adding a few more fish as my focus is more on coral. However, I definitely want a male swallowtail zebra angelfish.
I would like to know: Should I add one or two more females- hoping that one will convert to a male- or should I add a male?
My concern is that my two established females are fat and fairly aggressive already. I’m not sure what the best course of action is. Maybe I should just ensure that I get a large male? Or should I get 2 more females and spread the aggression a bit and let one naturally dominate?
Thanks for any suggestions.

 

[cdemoss01]

2 females could be aggresive yes.. if it were me I would go with a male just so I wouldn't have to maybe separate the females.