I really like Powerful Love for a first dance. Listening to Strangers, which I like too, it sounds more like a recessional to be played as the guests are leaving the ceremony. I think because its more upbeat. You could play that song after Powerful Love and invite the guests to join you. Either one you choose is lovely, though!
ETA: You could play Strangers during the cake cutting if you don't already have a song picked out for that moment.