My name is John Jones, I work with the police. I am also from Mars and use my skills to help others whenever possible.
Technically, I wouldn't be stuck on an island since I can simply fly off from it. But supposing that hypothetically, I am stuck on an island, here's what I'd like. My gun, knife, and a book about ancient civilizations. I'd want an endless supply of Oreos.
And as for people.. Clark would definitely be someone I'd want on my side there. And Arthur Curry, he could be very useful too, considering we're surrounded by water.