Well I never went fishing down there when I visited, but I do recommend Clifford & Eric as excellent guides (Steve from Coconets set us up with them). My friends and I went snorkeling with them, and they did a fantastic job and I know that they also take visitors out for fishing, diving, beach B-B-Q, etc. I've actually remained in contact with these guys and you can call or email them at 011-501-600-4448 or [email protected]
It seems that there are many good guides in San Pedro, so I'm sure whoever you choose you will be happy with them. Best of luck!