Generally I would recommend the same flex in your driver, so if your favorite club has an S flex then the flex to consider would also be an S. That being said, not all S flexes are the same and a Hybrid S flex and a Wood S flex will have different profiles and most likely weights. So, I would look at S flex driver shafts in the weight that you prefer that have a trajectory profile that matches what you are looking for. We carried the ZT9 iron shafts a few years ago but not the hybrids. My guess is the iron and the hybrid are very similar. The iron shafts were a Mid/High trajectory profile so if that is what you prefer, you can look for driver shafts with that same feature. That is about all I can offer without actually fitting you or having more information about your game, information on what driver shaft you are playing now, and what you are hoping to improve in the performance of your driver with a new shaft. On the UT driving iron, you could try a similar shaft to the ZT9 if you feel the driving iron is a club option you need. If the hosel diameter is .370″ on the driving iron and you want to try a shaft similar to the ZT9, the closest thing we would have would be the Recoil ES Hybrid.