Lovely action shot yo have going on there, well done. I feel though the photo is slightly over exposed especial the middle of the fuselage.The rear seems a little soft with the front being preety nice and spot on, if you want send me the original and I'll have a go at it for you.
It's a lovely capture, but in it's current state it will be rejected I would say. The fuselage seems slightly overexposed, so if the image has been lightened, re-edit and be more gentle. Also, the image is a little bit soft, especially to the rear of the aircraft. I think resizing to 1024x683 would benefit it.
I'm not sure which one has the better chance to get accepted but I personally like the 1600 better as well. Usually when it's 1600px wide it's gotta be really good to get in though, because the flaws are easier to spot, but I think your photo might have what it takes.
Canon 40D + 24-70 f/2.8 L + 70-200 f/4 L + Speedlite 430EX