A good quality ship component gives either -1 power or -1 space, whereas a best quality component gives either -2 power, -2 space or -1 power AND -1 space.
Power or Space requirements are not allowed to drop to 0. if that happens, treat the component as incredibly beautiful instead, giving +1/+2 morale.
Using this rule you don't have to deal with 40 special rules for 40 different components. and it allows you to cram more stuff into your starship.