First horse, I don't like how all the shots are on an angle. It gives you a false impression of how she looks IMO. Though since you don't have a problem training a horse, you might want to look into her.
Second horse. No conformation pictures, no pictures of her without a saddle on. The description says she has spots on either side, but for me, if I can't see it, I don't believe it. They also don't give an exact number of years since she's been ridden. Was it 2? Was it 3? Was it more?
Also how they worded that her daughter's show horse is now her trail horse, is that the horse they have for sale? Maybe it's just me, but I found it confusing.
Third horse, she's a nice horse. Looks like she'll make a great project horse, and you won't have to go about introducing the saddle and everything.
I guess it really depends what kind of training do you want to do? Do you want to have a 2 year old? Or would you rather take on an older horse?
They all seem like a good training choice to me.