i think he means headers that will bolt up to the stock exhaust w/o any modification to any part of the exhaust. i know cause ive been looking for something like that for my CRX with a b18c. basically, they dont exist. your going to need to get a header for your engine, then modify the cat with the proper flanges, or get a custom pipe made, so that everything will bolt up. if you dont car about taking it off at a later point, the just get it all welded together.
edit: maybe with your civic the header for a b18c WILL bolt up already, but im not sure, all i know is that it wont in my case.