Due to your unsure-ness and general anxiety about not knowing what you like and fea of commitment, i would suggest leasing a horse first. Leasing a horse is a great option for those looking to gain confidence in their riding capabilities, develop a bond with the horse, learn general care of a horse, and get into a routine. You could even start riding at a barn with multiple horses available for lease so you could try different breeds, disciplines, etc in order to find out what you like and don't like in a horse. Plus, leasing a horse is a finite agreement so if you think you like the horse at first, then end up wanting to try something else, there is no long-term commitment like purchasing a horse would have. Good luck to you!
Oops- didnt read the post where you explained you already have leased horses before... either way, leasing is a safe option if you are not ready to take the "plunge" of purchasing yet :)