As far as my reduced knowledge about analog film cameras goes, I think that you should go for a 1.3x anamorphics due to the aspect ratio of the gate, since with 2X anamorphics the gate itself would crop a lot on the sides. That said, if you want my two cents, when it comes to choosing the combo camera-glass, always do your own tests and (if you can) try the actual Combination and see how it looks. Don’t let others than your project tell you what’s best. Good luck!!