W4e need more information to make a decision
Dressage horses (18-20 yo) -
What Level are they trained to?
What level were they shown at? What were their scores?
Were these shows USDF/USAE shows or local shows? (Note local (aka schooling) show scores are USUALLY better than the offical (USDF/USAE) shows.
How long ago were they shown?
Are they still being ridden regularly?
If not being ridden regularly at that age you'll encounter issues trying to bring them back into shape. Also - although they are trained their age will probably limit the level they are likely to attain (the older they are the harder it is to carry weight on their butts - which is what you need to do well at second level and above).
OK - just noticed you want to event - so do NOT buy 20 year old horses for eventing.
I tried to get all this information, but the mother doesn't know anything about the horses (the one I was communicating with). I didn't plan on getting the older guys for eventing- I planned on getting them to teach me dressage. Eventing comes later, with a different horse
Thanks for your guys' help! I've decided to pass on this thoroughbred gelding (and the oldies!) after some critiques here on HF. I'm currently on the hunt for the perfect prospect in the Iowa/Illinois/Minnesota area! I'll post any pictures of prospects here for critique as they come up! I've starting communicating with an eventing trainer here and may go take a lesson with her once or twice in the upcoming month. Depending on how things work out, I'll also be checking out a few of the others until I find one I really like.