He won't be ready for a hiking harness until he has
achieved full growth, as well as able to leashwalk with a flat collar and leash...and... grows into his brain.
At that time, I recommend a Ruffdider Roadie Harness for hiking. It has attatchments for collapsable bowls, water packs, first aid kits, etc. Another advantage is it doubles as a saftey harness/seatbelt for your car. It comes in a variety of prices depending on what you feel you need or afford.
Ruffrider.com | Dog Seatbelts | Car Safety Harnesses and Pet Safety
I use mine all the time with the girls!
PS: Harnesses designed for pulling are entirely different.