I'm sure Stype will perform well for what you want (none of the twin cams need loads of wind, and they all have great low end power), but I'll comment on something else.
I haven't used that combo, but on North Daytonas that I use, I didn't like performance of that Carbon xTender. At all. Try your sail with the xtender, and then with a proper longer mast, borrow one if possible. In my case there was a world of difference, maybe they work better now.