Some people have answered your question in a round about way. I think most are uncomfortable saying that a pad they haven’t seen/used etc is a good idea. Multiple people have recommended looking at Acavallo pads because they have used them and know the quality and the happiness of the horse when riding in them. I would back up that recommendation and they make pads similar to what you have linked to above but in my opinion nicer.
The acavallo pad I have has helped my saddle fit a wide variety of horses comfortably and stay put. If I were to order another I would likely look into one that is more than just a gel pad but would stick with that brand because I like it.