The last time I used HorseSaddleShop they offered to send a shipping label so the return shipping was free. Maybe that was a special at the time I tried a saddle from there. They do have one of the best USED sections for saddles, IMO.
I'd recommend getting something with the pommel like a western saddle that you can add a bucking strap too. Grabbing the horn doesn't actually keep you stable as it encourages you to pull yourself out of the seat.