Oh, I love Garunteed Gold, not my favorite of dilute thoroughbreds, though.
I believe your boy is what I call a brown buckskin.
Nice little head, thick throatlatch, attractive neck, it looks really nice. Shoulder is good, not great or excellent though. Nice withers, but he looks a little wonky in his knees. I like the length in his front legs, and he seems to have good pasterns. I am really not very fond of his whole rear end, he is a little butt-high and I don't like the angle in his hind leg. Loin is a bit long. Pasterns and hocks seem a little posty. He is toed out in his back feet. He should grow into his bum though, and it should look better with age.
He could use a little conditioning and work, he would benefit from dressage, and I think this is what he's be best at. He needs some work on his topline.
He seems to have lost muscle condition and gained weight in the more recent photos.