Well, horses live a long time so would you want to start out with a youngster or an adult? Even a 20 year old horse can still be a good riding horse and companion for ten more years. Be realistic, when you think about where your life is going to be in several years do you see still having a horse. There are a few horses that need to be adopted in the Oregon area. You'll want one that's gone through training and has had a younger handler. This one is young but has already gone through quite a bit of training with a young handler http://www.petfinder.com/pet.cgi?act...=0&tmpl=&stat=
It may take a while to find te horse that's right for you so be patient.