With whose stories does Krakauer follow? For what purpose?

I'm not sure what you mean here. What chapter are you referring to?

chapter 8

Gene Rossellini (not sure if thats correct spelling) aka the mayor of hippie cove went off into the wild of Alaska to see if he he could live as primitive man would have. After doing this for 10 years he declares his experiment a failure and leaves Alaska stating that his next goal was to walk around the world, but before he did this he commited suicide (in a most metal way).

Everet Ruess- Someone who is much like Chris to the point that their story is almost exactly the same (intellegent, charismatic, individualist) except he disappears in Utah and is never found again

Carl McCunn a photoghrapher that decides to hike into the Alaskan Bush to "live off the land" like Chris did except he was a lot less smart and had a hut with provisions, he throws away his shotgun shells because he "felt silly for having so many bullets" so after he gets stuck there he runs out of food and begins to starve to death hes at deaths door when an airplane flies over. Thinking he is saved he runs out and frantically waving both arms over his head to get their attention, unbeknownst to him however this is the sign that everything is honkey-dorey and they fly away leaving him to his death.

These are included in the story to show the comparisions and differences between McCandless and others who have died in the wild as well as showing the critics perspective of Chris wich Jon cannot rightfully show because he is strongly for McCandless.