ive got a 1999 honda civic SI / ... b16 vtec

i pulled the head off ... and im getting a new gasket ... my car has nitrous on it .... is it manditory to put a steel gasket on if the car has NOS .. the gasket i removed still looks good and the numbers on it are . (PR399111) and it has steel rings .. but its not completly steel ..

also ... do i have to get new head bolts or is it just recomended .. .

and what are the torque specs for my engine .. b16