All else being equal, I'd personally go with 2+14 and Ambien (or whatever floats your boat in that department). An eight-hour flight, by the time you factor in all the stuff that goes on at the beginning, at the end and at mealtimes, is too short to get as much sleep as I'd want. YMMV.

The airline, aircraft type, seating and mileage earning (not so much 400 more miles for the CDG routing, more how the fare classes I'd book are credited to the program of my choice) might affect my choice, though.