My 2 cents:
I would not choose Thor because his speed (or lack thereof) seriously gives me some major concerns...I prefer a hero who can get from point A to point B very fast.
I would not choose Hal for the fact that he is a mere mortal behind that ring of his...
It's kinda tough between Surfer and Superman. Surfer is the more versatile one and perhaps the more powerful of the two, but I would ultimately choose Superman. Superman has a better attitude imo in fighting villains....he's more apt to go all out and he just seems more fierce a defender than Surfer would be. Surfer's a bit aloof, whereas Superman will bring his A game from the getgo.
So my ultimate choice is Superman.