Will, we seem to have concluded that you need a 17mm wrench, vice grips, and another human in addition to your 10, 13, and 15mm wrenches.

he doesnt need another person, he has air tools

Will, that is Gearwrench, correct? Same wrenches as mine, good quality IMO. Here are the sets I have. $30 each for the stubby sets and $35 each for reversibles... Your approach makes sense for you but I work on everything so I need metric sets of both. These 8 piece usually cover my needs but I am missing a few. I would like to hit a sale on individual wrenches, I need a a couple more sizes.
http://www.sears.com/shc/*/p_10153_1...sName=Wrenches
http://www.sears.com/shc/*/p_10153_1...sName=Wrenches
I'll get the sets on sale, you pick up the individuals on sale, and we'll trade. haha Seriously though, if you ever feel like you need more, just watch Sears. They put all of their Gearwrench sets on sale 50% off quite often. The flex heads will be next for me.