I had a flattish swing plane for much of my competitive playing days and although the lower trajectory wasn't a huge disadvantage most days, I would experience a noticeable loss of distance playing when the conditions were soft, like after a couple days of rain, etc. So I got this idea that perhaps a high-lofted driver might help.
Except being left-handed, there were hardly no options. But I did notice that Ping made ladies' drivers in 14º, lefty. So I bought one, I think it was the ladies version of the G5 driver (I seem to recall it being called the G5 L). I swapped out the shaft from the current driver I had been playing, and it was great. I was carrying the ball about 15 yards further, so I started seeing less distance loss when the fairways were soft, but noticed I was getting even more rollout when the conditions were dry. I'm guessing the net gain average was probably 20 yards.
To this day, I've yet to play a driver that was as consistently long and straight as that one was. I eventually gravitated to the adjustable loft variety, but honestly I didn't hit the ball nearly as consistently well as I did with that lady's head/shaft combo.
Not sure if you can find one, but perhaps it's worth looking into.