"would stylesheet changes be for the entire site?"

Not at all. If you use unique class names for these bits, any styling in the stylesheet will affect only them. Even if you don't type each one in now, if you ever wanted to make any change in the appearance you would have to edit every single product separately. All of the font/size/color and much of the spacing can be controlled through the stylesheet, with one edit affecting all comic listings at the same time.