The Glock will be the lightest, but you REALLY need to rent/try all those firearms first. Especially the XD's, and XDm's if you're thinking about that. IMO, the XDm trigger is a LOT better than the XD's, but SF will switch the trigger for you if you call them and complain.
Moral of the story, try them first. You should be extremely comfortable with the firearm you trust your life to.