Kingsize. Some of their shirts have a longer length option that adds an inch or two to the length.

I used to have the same problem. Then I realized my hair is thinning, and any style haircut I wanted would never look how I expected due to thin spots. So I just have them shave my head. #0 or 1/8th inch. Go back 2-3 months later and repeat. Try it. If nothing else, it’ll grow our to about the length you want on top, then just have them trim the sides down.