bibs/boots for very tall fisherman

my brother is just getting into striper/tuna fishing. was thinking of getting him bibs/boots as a present. only problem - hes 6 foot 11 and wears size 18 shoes. does anyone know where i can get deck boots that big? or where to get bibs? most of the 4xl bibs i looked at were wider but not necessarily longer(hes only 225 pounds) any help would be appreciated.