Cab franc is normally considered a blending grape, not sure how prevalent it is there. It's really dependent on your local conditions. I found someone here that let me choose my rows, take brix readings and do the pH/brix ratio and then chose when to pick them myself. I did 1 1/2 tons of fruit that way a couple years ago. If you REALLY want the experience, that's the way to go. Otherwise, I'd contact local vineyards (not necessarily winerys) to see if you can pre-contract for some fruit.