Alliterative names are the best. Be not afraid.
Quinn for a boy is cute without being too childish. I like it. It's got a rogue's flair to it.
Here's some stuff:
Quinn CaseyQuinn MorganQuinn KentigernQuinn DagnyQuinn ChristopherQuinn HenryQuinn NathanielQuinn VincentQuinn MaxwellQuinn TheodoreQuinn Marcus