Paint, reman. and most " new" coatings on booster suck and start rusting fast, trim coat works well if you want the satin finish just prep and clean it well...
i do trim coat since I all ways have a few cans of it, its close to the oem finish. The last 93 cobra booster I got from cardone was pitted badly and silverish in color, coating flaked as you touched it. Used some poly flex and self etch before the trim coat to clean it up. Did the same for the wiper motor., color I guess what ever you like. Only thing I hate are lazy all black rattle can bays, these where cardonecardone remans, I haven't tried the cheaper skp repop stuff yet
Paint it. That Cardone oxide finish will rust up quickly. My first one I left plain. It looked like crap in a few months. The last one is painted and still looks great.