After 9-10 months of waiting, someone finally made a Saiyaman mod over Gohan, and just in time to be an entry in the Costume Modding Contest believe it or not!
Comes with 2 versions: Helmet and Headband. See Installation for how to pick which one to use.
Also thanks to Saitsu for making a pretty hecking cool Color12, I'd suggest checking it out!
WARNING: When selecting Frieza's Color13 or Color14 (or when fighting a Goku Clone in story), the game may crash (as in it probably will) due to how the mod shares assets. Just be careful with that.

Simply delete the "~Headband and Cape Patch" folder in the main mod folder if you want the Helmet version, otherwise keep the patch if you want the headband/glasses version.