I've only seen parts of the two episodes in the tropical areas but did see the whole show on the African location. I was thinking at the beginning that my one item would have been shoes or boots. My feet are tender and wouldn't be toughened up inside of 21 days! Everything else is easier to do if you can walk without worrying too much about stepping on thorns, hot sand, sharp rocks, and stubbing your toe.
Kelly did pretty well, I think. I noticed they did show her making cordage a couple of times and to have the forethought of bringing a water carrying vessel was useful. She also made a comment about her being on her "cycle", what a tough thing to have to deal with during the time in the wild.
I was really expecting to see the guy grab a good stick and use it early on for a walking stick then later a spear. It took quite awhile for him to get around to making a spear. Also, a throwing stick for birds and small game would've been fairly easy to find or fashion with minimum time involved.
I'll for sure watch Billy's episode, I hope the editors don't make him look like a dope.