hehe I am of course only messing... Cosmetic upgrades are all down to personal tastes anyway. Although I do think I could do better than that with a dremel.
Since its your sons ion, heres a good plan: If hes been good all year, get him a lucky stage 5 for Christmas. If hes been bad, get him the trinity kit.
That way, when he complains that his guns too heavy, or asks why he has to take his whole gun apart to get to the eyes. You can say 'you should have been good all year shouldnt you?'