My father is 6'4" and he went on his first trail ride with us on a Standardbred in NZ.
He was fairly tall and stocky and my dad was very comfortable (his first ever time on a horse too) and his legs weren't dangling either.
I think you should look for something with substance that COULD easily do trails and endurance.
I think your husband is looking at their beauty rather than their build and potential.
EDIT: Something like this?