Very hard to tell from the pics if any of these will be able to compete in what you want. Especially hunters and dressage. If I had to choose one of the three most likely to succeed in those disciplines, I would choose the TB. If you want gymkhana more, I would go for the first one. Same for trails, etc.
I really think the left rear pastern issue is angle combined with the boots on him.
Every horse does NOT have the ability to jump and compete in hunters. I have one. Jumps really UGLY, but is great at other things. You won't know until you see them, IMO.
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