[neutralino]

I would say that the answer to your first question would be yes. If there are infinitely many other universes that make up the multiverse, then yes, there will be infinitely many other "yous." If you believe in the many worlds interpretation of quantum mechanics, then this says, in laymans terms, that when there is a decision to be made in a universe, two universes are created which are identical up to that point, and each have a different outcome of the event in question.

To your second question, I have no idea, but I would imagine that they would have to be in some sense "close" to our universe.

There's a new book that's come out called Universe or Multiverse. I've not read this, so don't know the level, but there are contributions from a lot of big names (Weinberg, Rees, Hawking, Tegmark, Susskind, Hartle, Carter, Smolin, Ellis, etc..). It might be quite interesting, if you like that sort of thing!