How do i get a pair not to form

Probably not possible, the only way to accurately sex an angel is when they are spawning, at which point you will have a pair, and have to remove one of the fish. I don't think there is any way you are going to be able to prevent a pair from forming.

I think the only way you could get away with 4 angels in the one tank, would be to purchase mature all male or all female angels from a breeder, even then you might get aggression issues between them and not be able to keep all 4.

You should also be aware that 4 angels in a 45G is going to be pretty crowded.

Even if you put in all females pairs can form and cause all the same problems as a normal pair except for actual production of fry. I think your expectations are a bit unrealistic. Wanting something badly isn't going to change the fishes' behaviour. The surest way to avoid problems is to keep a single.

Luck in the selection is the only way I know. Aggression may still occur even if you get all of one sex - angels are ciclids and they can be aggressive - usually when there are only a few present.

It's pretty much a pair or a single angel in your case.