Horse Country in Warrenton, Va has shaped pads made for the Jeffries Flyover- might work for your saddle. I think about $50 each, have the grippy things on the withers and girth loops. PM me, if you're interested, I'm not using them.
So I got the Beval fleece pad. It's not my favorite type of fleece but it will do for schooling. I ordered an 18" because most pads are too small in the seat area for my 17" saddle. I probably could have gone with the 17" in this pad. The forward flap works well though.
I do think this is the same pad that Equusnow sells (wilkers) that you can customize. I'll probably get one from them in a 17" and see how that works. Theirs is also cheaper.