It's just that people with as much experience as you're describing usually don't ask random chicken-site folks for advice about horses, especially from photos where you can't really *see* the horse well *anyhow*
But, there;s a first time for everything I guess. If your concern is that he's not a breed you're familiar with, rest assured that a horse is a horse is basically a horse. The structural features that affect how the horse moves and how well he stays sound, and the mental features that affect how trainable and enjoyable he is (which can't be assessed from a photo anyhow), are the same in any breed. Obviously QHs move differently than, like, Arabs or WBs, but if you *want* a QH then you must *want* that kind of movement, so,
As for whether to buy the horse -- frankly it sounds like you really really want something you can start riding NOW and in my opinion it is in this horse's best interests not to be ridden for the next year or two at least. (Obviously some people DO start and ride 18 month old horses, heck some people start and ride weanlings or just-come-yearlings, but that does not necessarily make it a good IDEA, especially for the horse's soundness ten years down the road)
So speaking for the horse I would argue for your giving this one a pass and keeping looking. JMHO of course.
Good luck, have fun,
Pat