Formula????

Okay so my fiancé and I are trying to start stock piling things for when the baby comes, like diapers, wipes and we've talked about getting some formula stocked up so it'll be a while before we need more. (& ive heard all the "breast is best" arguments but it isn't going to work for me due to medical reasons. So please, just answer my question) but I'm a little afraid to buy formula in advanced because I have no idea what kind to get! Since I don't know if he'll be lactose intolerant (I am, but I don't know if that matters with formula ???) or any other digestive issues! (I've had problems eating/keeping food down since I was born). Should I hold off on formula until I see what he takes well to? Or is there a good type that I could stock up on? Or different types maybe?? Please help! I'm trying my best to be ready but I'm stuck!