Thank you so much for the replies! So helpful!
I actually have a question, kind of stupid, but again, I've been a dog show person for all of my life. Does a horse have to be pre-registered for it to be entered in a show? For dogs, they have to have a pedigree with registered parents, grandparents, etc for them to be shown in certain sports, like conformation or field trials (AKC rule reference). However, I can take any dog (mix, purebred, registered, not registered, etc) and register it in AKC then compete in a large range of other performance sports. What about the horse world? What organizations and how would I register a horse do I need one already with papers?
So, I was thinking Arabian or cross, but do you think they will be bad for western sports? Could they handle eventing? Thoroughbreds were also on my list. I read about the conformation problems. How hard would it be to find a nice one? Also, could they handle the sports I'm interested in?
So, conformation wise, I should be looking for something with powerful back legs, right? Ah, I only know basic horse conformation and all dog conformation knowledge.