I agree, that for moving up in competition, that horse is not a very good choice. He would only last up to maybe 5 years before he would have to be light work only, if not before that. I guess I failed to mention that. I meant to, but I guess I forgot.
IMO, the mare Almond Joy mentioned (I don't remember, but she really stood out in my mind) is the ideal choice for moving up. She is my personal favorite. Lots of confidence (I presume).
By the way, 14 is not senior. 12 is definitely not a senior, 15 isn't either, but 18 can be showing some signs
When I said 'regular exercise', I didn't mean that you should go out and buy a [still able to work] geriatric horse. Obviously, he can't be put into hard physical work, like jumping, which is hard on the joints, at any age. I was just giving an example of how old horses can still work [lightly], and horses vary by individual, I think FeatheredFeet gave a better example of this, tough :/