Sasuke has better chance, due to already progressing his Sharingan to EMS, and all he needs is Senju genetics. Naruto has to take in, Senju genetics as well as implant Sharingan to evolve.
He is still alive Kishi just showed you how,By Madara vomiting the tools of the SO6P. The Gold and Sliver Brothers Yin and Yang Chakra of Kurama is their along with the chakra of the 8 Tail in the severed arm. And the gore that can take the Tail Beast away from Madara, found by Gui,Lee and Ten ten who are following Naruto.