You're overthinking this. Seriously, you are. You can use software like Topaz Lab to reduce grain or add pixels. The quality of your lens is going to influence the quality of your picture more than either of these bodies will. Both of these bodies are roughly equal--six of one, half a dozen of another.
The "feel" and ergonomics of a Nikon are very different from a Canon. Most Canon users pick up a Nikon and go "weird" and Nikon users have the same reaction. That's because that while these are relatively equal cameras in terms of performance and what they'll do, they will feel different. Go to a camera store and hold each one, go through the menus. See which "feels" better for you--more of a fit--and is more intuitive. Then make your decision.