ORIGINAL: North Texan
Welcome to the forums aaronkash!
With good quality optics, a 40mm objective is just as good as a 50mm objective. For most hunting rifles, a 3-9x40 is an excellent choice. Leupold is a good brand. They have the best eye relief of any scope I have ever shot. Gloss is a shiny black and matte is about as shiny as most rifles. As far as duplex vs. wide duplex, that's just up to personal preference.
I agree with North Texan, not much vissually difference betweena 40 and 50 considering good optics, Leupold does have very good eye releif, but the Simmons AETEC is slightly better and offers constant eye releif, if you find that a plus (I do).