Bobert, There are companies that make a two part(catalyzed), water based paint, that is incredibly durable. It also is thick, and should fill the uneven areas, being as it is self leveling. The product is a bit more expensive, itself, but the labor it will save you, plus being so durable should pay off in the long run.........or ask Obama...he has a good rap for everything...(wink)
Pacific Coatings make such a product. I've used it...It is really amazing!