If you are serious about getting better, then I would go with the blades (MP-67's) I have a set of MP-37's in my bag, and yeah, they aren't as forgiving as cavity backs, but it will make you focus more and in the long run will help your golf game. There was a comment that Nick Faldo made and that was that you should learn to play golf with a set of blades, and then when you are a good golfer, then change to cavity backs if you want.
There is nothing wrong with a 14 handicap getting a set of blades. One of the best feelings in golf is when you pure a blade. If you don't feel comfortable with the MP-67's then go with the MP-60's, but don't go for the MX series. Whatever decision you make, trust your instinct. Whichever one you feel the most condfident with when you set up to the ball is the clubs that you should choose.