I am going to feed a 125 or 200 amp sub panel off my existing 200 amp service from my residence which is about 30 feet apart. Installed at the house a Westinghouse WMB 202040S load center. I see no means of adding any lugs to the main breaker. I was considering tapping the lugs or finding a lug kit and feeding off of the existing incoming busses and utilizing another 200 amp panel at the new building with a main breaker included. Would this entail getting a lug kit from Westinghouse or just some run of the mill lugs at the electric supply house. I did not seem to find any sizeable feeder breakers for this type of box that uses the BR type breakers. Since I am going to feed off the service incoming wires, should I utilize a grounding rod at the new building. I have seen some talk here about whether to do that or not.