I don't know of any place to look for "counts". I don't think that when it comes to meat kashering that you need to worry about salt content today as you would have years ago. Years ago, meats were kashered in smaller size pieces. Today, most large butchers and meat packers kasher larger sections of meat in big vats. Just eliminate the added salt in cooking. Meat you should stay away from however, are tenderloin and skirt steaks. I find them to be quite salty. Stick to steaks that are cut from larger cuts of meat such as Rib Steaks, Shoulder steaks & Minute Steak.
As for chickens, occasionally you find some a little saltier than others. I don't see how soaking them can hurt. Make sure you soak in cold water and in the fridge.