Don't do it. Angels and bettas do not get along. I don't know about the bala's either but in my advice would be not them either.
Also two bettas is never really good in one tank. Even females, the females need a min of 4 per tank to be in the same tank.
I am sure there are others who will answer who know much more than I, but there is my opinions.
Bettas - TOTAL COUNT - 18
Thoth, The Red VT twins - Fred and George, Motoko. As well as Bloodmoon and SilverKnight, Zypher, Bobber, Quetzalcoatl, Tsuruko, Shinobu, Mistume, and Su. Introducing, The Duke. 4 unnamed.
RIP- All those loved and lost. Forever Missed.
I now add the name of Prince Poppycock to the list. forever loved and forever missed.