How tall are reining horses usually?

How many hands high is the average height for reining horses. For example how tall ares some of clinton andersons horses that he reins on cus he seems like a tall person or at least taller than me? I want to get a horse that I could possibly train to do reining but I am really really new to it so I need some info and a horse that will learn with me and still be good at the job.