If you want a sport horse, then the taller colt is the only option here. He has a much better rear end and will probably be able to jump, at least small jumps and maybe a lot more than that.
Heads on both will be acceptable, but not gorgeous. Freisans aren't noted for pretty heads.
Neither one of those colts is stallion quality, I don't care what country you are in.
I've driven a lot of horses and I've owned half a dozen stallions and there is no way, under any circumstances, that I would use a stallion as a driving horse anywhere else except inside a riding arena with trained handlers standing by. You must be able to trust a driving horse 99.9% every second that you have them in harness. Even the very best behaved stallions, I would never trust more than 30%, and I have owned and been around some very steady good-natured stallions---- all of them pure western cattle horse breeding or draft horse, and not ever one with any sort of hot blood.
A few seconds of silliness with a saddle horse and you can usually go with them and get them under control again. A few seconds of silliness in harness can result in broken equipment, severely injured drivers, injured bystanders, broken legs, and shafts through the horse's belly. Don't do it.
Stallion quality is a stallion that can make a positive contribution to a breed. This colt is an unregistered crossbred & isn't for breeding unless my friends want to put their local mares to him for improvement. It's usual where I come from, to use Friesian, Welsh or Arabian stallions for driving out. The Arabians in Africa are very quiet when not show bred.
I'm trying to decide if I want the less flashy sporthorse for mainly riding with the risk that he might not grow out the way I want him to or the smaller hack/harness horse for pure flamboyance & predicable Friesian like conformation but limited & not particularly special except for color & flashy movement.
The owners have no reason to lie. The colt is "what you see is what you get". The only point they made when showing him to me is that he is a purebred Friesian and is imported. The photo I took was to show his temperament, not his conformation. Their other horses are very valuable & this colt is just a side project.
I would have no qualms about driving a stallion. Especially with that Friesian influence. During their 50 day stallion tests, Friesian stallions are driven in the arena, out on trails and on public roads even with other horses being ridden and driven. No big deal. Friesians have low reactivity and great tractibility, and their hallmark as a breed is driving. As a side note, I think Friesians have fine heads, now my TB mare, that's another story LOL!!
They are both very beautiful in coloring. #1 is more flashy- I like his coloring better. Personally for myself Iwould take #2 since you said that he seems gentler. You sound like you really like #1, so I say that you should get him. He looks like the nicer colt, I just have a sliht fear of hyper/not fully trained/ young horses that could buck me off. My ideal horse would be 15, calm, and gentle, lol.
is there anyway you pay a deposit and could take each of the colts for a couple days/week so you could get to know them better? Anyway, #1 or 2 I would say #1!