I just went through almost the exact same thing. When I was fitted for a CWD, the rep came out, carried two saddles to the ring, and stuck one on the horse I was borrowing for the fitting (I do not own one and didn’t have a lease at the time.). I took the horse through his paces and jumped a couple of jumps, tried half and full-seat. I tried three different models total, and every time told the rep what I noticed that I didn’t like, or what I noticed that I did like. It was low-stress, no pressure, and my rep was very easy to work with.
I didn’t actually make any decisions about what length or angle of flap, nor the size of the seat when I bought mine (I later freaked out about it- I was worried that it would end up being wrong, and that it wouldn’t fit the OTTB with a shark fin that I started leasing post saddle-purchase, but it turned out to be me having a meltdown for no reason :)). The rep recommended what he thought was best, and my trainer, who had been present to observe all of this, agreed. My saddle came in a couple of weeks ago and, after the initial ride where I was nearly convinced I would need to return it, it has started to break in and is heaven! 
Good luck in your saddle shopping adventures!!
