i always say that it depends on the horse, but overall, i definately do not think that 18 is too old. our mare still showed at 38, had her last show about 3 weeks before we unexpectidly were forced to put her down.
our two best lesson horses are 17 and 21. they go to shows almost every weekend with multiple students and are always in the ribbons! the 17 year old maxs out at 2'6, he mostly does up to 2'3. but the 21 year old is still doing some 2'6-2'9 courses. my friends horse she leases is 22 and was just retired from 3'3 (started out at about 3'6-3'9 when he was younger). shes doing 3 foot with him.
i just met a woman last show season that has a 31 year old ottb gelding. she is showing him consistantly at 3 foot.
obviously with an older horse, there will be some maintence, especially since your doing hunters and jumping. maybe you will have to get him injected once a year, maybe at home you can only jump 2 foot and at shows do the higher fences, maybe you can only jump once a week at most. it really just depends on the horse, but i think its worth it!
EDIT: i didnt thoroughly read the whole thing and just saw about how he was a hunter horse so thats what i talked about, sorry! but if your only doing pleasure stuff on the flat, i would definately go for it! especially since hes had the past few years off, that means nothing strenuous was done with him so he doesnt have that "wear and tear". just make sure you try him and get him vetted and if he passes and you still think hes a good match, then id go for it!
im also not one to get an older horse, but i do think it depends on the horse, what you want to do, and what your goals are. it sounds like you have it all figured out and i really think it would work and sounds like a good situation!
Last edited by khorses23; 03-07-2016 at 10:40 AM.