If the elements are going to be an issue for you guys, avoid the upper deck. It gets much windier up there. If you go for the lower bowl, sitting up a little higher is better to see more of the game. Also bear in mind your wife's height. Mine is 5'0" and we sit in row 15, which makes it easier for her to see. She also sits right on the aisle, so that helps reduce the number of people blocking her view. if we sat any lower, she'd have a hard time.
Edit: I should also throw in a plug for where we sit in particular, lower bowl corner, tunnel end, Bills side. Sections 126-127. When they show Elvis or the guys in the chefs hats on TV, that's the front row of our section. Yes, being on the end, half the scoring plays happen far away from us, but when they happen in our end, it's cool as hell. I've said it before in other threads, Sammy's first career TD, that kick Spiller returned for a TD against the Fish, the time Johnny Manziel got pasted by Kyle Williams, Salas' TD flip into the end zone last week, those were all pretty great moments that happened right in front of us. Plus, in our particular corner, we get to see all the Bills luminaries as they walk out of the tunnel and toward the bench. Jim Kelly, the Pegulas, anybody and everybody.