This. Especially considering the fact that a single feat can make up for more than 2 points of con missing. I know that pallies are feat-starved, but your statement is simply refuted by the existence of the toughness feat.
Here's a thought for the OP: Did you consider 18/2 (monk or fighter)? You will miss the Capstone, but you will be a lot more relaxed on the Stats - a mere 15 Cha is enough to get to the highest tier of DM available, and the two extra feats can be used to compensate for not enough HP, OC prereqs, or other nifty things.