Sorry to hear that, Mike. The price we pay sometimes for living on the coast, huh?
Since Katrina, I've used a lot of oil based Zinsser Cover Stain with good results in situations like yours. It's an all purpose, so no need for two different products.
Nestor, reasonable thought on the backer, but storm surge gets inside the walls, no matter what they're covered with, and in this climate you'd have a serious mold problem in a matter of days. Walls have to be gutted (if the surge didn't already do that) and dried out before anything else can be done.