I still say Quarter horses as a generality, have a good temperment. Especially the geldings. When you do go to buy this horse, you have to not let your heart run away with you, and really pick one that is broke and trustworthy. It may require a few test rides. It may require the purchase of a less than eye catching old horse. But just think of how hard it will be to want to get back on if you are scared or feel constantly overwhelmed.
Everyone has to start somewhere!!