In order from preference... #3, #2, #1. I think if you're looking to move up, a 15h horse is not going to be the answer... there are lots of really spectacular jumpers that get over 3'6 that are only 15h.. but they are special horses, and don't come up every day.. you're going to be more likely to top out at a specific height with a smaller horse than you would with something even just a hand taller (because height definitely is not always the answer either).. which again, is not to say it still won't happen with a taller horse, but it's less likely. 16-16.2 is a much nicer range to look in usually.
The dutch warmblood is nice.. but it says he's scopey at 3'0-3'9, and mentions he's done 4ft. I would make a point of asking if he tops out at 4ft, or if he still has potential to do more. I guess that would depend on the height you're planning on jumping to though.
The irish tb is lovely as well... but I would be curious as to why there are so few riding photos.
Either way... if you're looking for a pre-made horse that can already do what you want to do, I would go with the Dutch gelding... if you have a trainer and can bring a horse up to it's potential then I'd be looking at the irish gelding