Military ball gown- which dress do you think is appropriate?

Going to the San Diego Naval Birthday ball in October and I am wondering what kind of dress to wear. I have already decided on something long because I am know that young girls in short dresses just don't give off the appropriate image. I found this site and it has some lovely gowns, what do you think? I am 20, 5'2 and 160 lbs, slightly bigger on bottom with tone legs.

http://www.promgirl.com/shop/body_types/pear_shaped

I am really leaning towards these dresses-

http://www.promgirl.com/shop/dresses/viewitem-PD401775

http://www.promgirl.com/shop/dresses/viewitem-PD213969

http://www.promgirl.com/shop/dresses/viewitem-PD491529

http://www.promgirl.com/shop/dresses/viewitem-PD485707

http://www.promgirl.com/shop/dresses/viewitem-FA374339

Feel free to look around the whole site and comment with dresses you enjoy. I really just want opinions!