EBF to mixed feeding

[PretzelPrincess]

So due to ill health I need to start introducing formula for DS 7months. He has no known allergies that I know of.
What brand of formula has anyone used when making the switch? How best to drop bf? I have no idea what I'm doing

I used Aptamil and just dropped one feed a week. But my boobs were always quite adaptable My DD was absolutely fine and I managed to mix feed aswell for a while until she gave up bf herself at 7m x