Here's another thread about having a pond to grow fish to eat.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Main=15629&Number=196000#Post196000 I would not stock catfish, they aren't *necessary* and they will take up biomass that could be utilized by fish that you can eat.
I strongly advise to put in an aeration system, get a good fish feeder and feed quality fish food. That will allow you to grow more fish, and if things go south you just need to harvest a lot of fish out, preserve them, and then the pond can survive without air/supplemental food.
Putting the correct cover in the pond in the correct places will help the pond tremendously. A client has a bathtub for a pond and it's a constant battle to keep the predators down and even then, they don't have WR's over 90 because of all the exercise they get looking for food.