This one is an attempt to resemble the outfit of Sun Wukong, protagonist of Journey to the west, on Son Goku who was inspired by Sun Wukong himself,.
I chose the 4th super saiyan form because I thought his monkey features may have matched better with the outfit,
here’s a pretty known fact, Dragon Ball first started as an adaptation of the Chinese classic novel “Journey to the West” (1590) but then it changed path for editorial advices and writer evolution, becoming the manga we all know. Oh, if you’re wondering, Son Goku’s name is the exact transliteration of Sun Wukong from Chinese to Japanese and it’s written ”孫悟空”.
Be creative with your life, it is a journey, every time you reach your goal, it changes.