I also think he s stunning, and has a nice show record to back it up. I'm assuming you are breeding for halter?
Only thing that stands out, and is really minor, is his back pasterns are a tad upright (typical in halter), and he's slightly downhill. He also looks slightly mutton withered, and I've noticed that in his foals as well.
Aside from height, what else are you looking for in the stud?
Have you visited painthorsestallions.com? They have a wonderful selection of stallions!