Oh wow. He is LONG. In the back and in the neck. Collection will be hard for him and collection of some degree is very important for jumping. To get the striding you need to be able to lengthen and collect his stride on demand.
I don't like that hindquarter, it looks too small. He has a nice shoulder but a tendency to stand under himself in front and well behind in the back. That's not a horse that will find it easy to balance, and he may find it very hard to get his hind legs under himself.