If aviation is your first choice then get your eyes fixed then apply for aviation. Don't apply for something just to get in.
I don't agree with the second part of this at all. I applied for aviation (my first chioce and what I wanted to do), but put down NFO and Supply as second and third choices, respectively. The first time I got denied, but figured I'd still rather be a Suppo than a civilian. I swore in to Supply, and 2 years later (right prior to graduating), after 3 more redesignation applications, I picked up SNA.
Bottom line, I would've missed out on $60,000+ in BDCP money had I not taken Supply. Don't get me wrong, if you'd rather not be in the military at all if you couldn't be in aviation, then don't take the slot. But if you 'can't' get picked up for SNA, but would still like to be a Naval Officer, I say take the slot (and free money) and keep on reapplying for aviation. It worked out beautifully for me.