I am seriously leaning toward this one, just want to make sure I won't be hindering myself by not getting a clam-shell pouch.

http://www.maxpedition.com/store/pc/5-x-7-x-2-Horizontal-GP-Pouch-Low-Profile-116p767.htm

Actually though it probably wouldn't matter. This will not be a Rapid access type of equipment. Maybe this one would be about the best size wise.