tell you friend to buy my 181 watchlifes, im the same size as him and i didnt find the 181's too big at all...they fit perfect...but he should defintily go for something between 176 and 181
im 5"10, and find low 180s perfectly fine for park, if not a lil short. if they are stiff, you can get away a lil shorter, but if they are light and soft, id rather have 186-7s