I think Rudy would be a far more realistic option than Paul. Rudy is a sidekick in Memphis any ways, or at least he will be with Mayo there. I'm not sure that Memphis will really want to re sign him as I have said, it is not because of his game obviously, but Memphis is the smallest market in the NBA and with paying Rudy and Randolph a combined 30 million next year I doubt that they would be able to afford it and in a few years when Gasol and Mayo need their new contracts they would be paying around 40 million for Rudy, Mayo and Gasol, doubt that they want to do that really.
As for paul, I would love to get him as he is by far the best PG in the NBA, but I don't see that as very realistic. IMO Rudy would be an amazing addition, as would Danny granger if at all possible. Nobody on the roster is untouchable except LeBron so any position is up for grabs except the 3 (even though for Granger we would play 2 3s).