The poncho drawn here is the typical poncho from Cusco, Peru (the rainbow colors are the city's flag). A friend brought me one from a trip he did there, so I was able to use it as reference (photo by me lol):

The quechquemitl on the other hand, is based on the typical ones from the Huasteca, since it's been said that they may have originated in that region, and then spread to the rest of Mesoamerica:

Lord of the sun and sustenance and patron god of the Inca Empire. Without Inti there is no warmth, no vision, no crops, no rain. He is essential to all things. He is often the child of Viracocha, the creator god, or Pachamama, the earth mother, and sister to Mama Quilla, the moon goddess. Sacrifices were set aside for Inti whether they be cloth garments, blood, land, or food. He is said to have led the people to found the city of Cusco, central to the empire. Inti had three different forms representing different forms of the sun, possibly the diurnal stages or different heavenly associations with the sun: Apu Inti (the father), Churi Inti (the son), and Inti Wawqi (the brother). He is celebrated by the festival Inti Raymi, and his central temple was the Coricancha/Intikancha. The ruler Pachacuti is attributed with spreading the cult of the sun, and to this day Inti's solar imagery can be seen on different flags of various countries, such as Peru and Argentina.

Pantheon: Inca

Domain or Function: Protector of the Inca Empire, lord of the sun and sustenance that provides warmth, light, rain, and allows crops to grow.

Alternate Names: Apu Inti (supreme Inti), Churi Inti, Inti Wawqi, Inti-Guauqui, Inti-Huaoqui.

Character Traits: He was a god who provided for the people and protected them.

Visual Traits: He is most often represented solely as a sun with a face.

Symbolism: The sun.