Formula for reflux

My baby has had severe reflux since about 3-4 weeks old. We are giving him omoprezole but he's still really suffering. We have been using apatmil comfort milk but think it's time to try switching formula (he's just over 7 weeks) I know apatmil do a reflux version but assume will be similar and thinking a different brand might be better. Can anyone recommend a formula that's helped with their babies reflux? There's so many to choose from. Thanks