What should we put on our registry?

If you don't need it, don't register for it. Most people will just give you money with a nice card, anyway. You could have your family members and bridal party discreetly pass along the word that the two of you would prefer money to gifts but by no means should you EXPECT gifts (though almost all wedding guests bring some sort of gift lol). I would say that you should forgo the registry altogether. Just remember to send out thank you cards to every guest that attended and/or gave you a gift/money.