Which horse should I more seriously consider buying?

If I were you I would go with the second horse. It isn't as broke but it sounds like a good beginner horse. And yes a 15.2 hand horse is a really good height for a beginner. His age is good too because you will have more time with him and won't have to worry about him becoming hurt if you ride for long periods of time. Hope this helped, sorry if it didn't. :)