I'm 5'7" and around 10.5 stone. Can I get away with a cob type pony do you think? Currently riding a 16.2 TB but long term if I was able to get my own it would be a smaller, hardier, happy hacker type. I'm stalking Trina's Cobs on FB and wondering if the 14.1hh she has at the moment would be too small. Thanks!