Where can i get a 16 hand high or a 17 hand high riding horse?

I want to get a riding horse from a sanctuary but i don't know where to look. I cannot pay big money for the horse though. I have all the tack: Saddle,bridal, Numnagh. I also have experience as i use to ride but gave it up as i got a serious fright with my old pony. I also worked in a Equestrian centre too. I have horses that i do in hand showing with. THANKS!!!!!