All three of my bubs have had dummies and it didn't affect BF'ing . DD uses Avent dummies (as did DS2). DS1 used Nuk ones, but they are expensive!

Make sure you choose a brand and style that has been around for a while because it's stressful if you lose dummies and can't buy replacements!

Sorry your DD has reflux . I know of a great paediatric chiro that has great success treating reflux babies, let me know if you want the details