Which would be less likely to crack with age from the sunshine and the rain? Monofiliment or braided fishing line? Which would be more durable and why?

I’m going to try to start one of those “mom & pop” shops up for used fishing reels, rods, lures, sinkers, bobbers, etc. with some of my friends & family and was wondering what are all the necessities? I have a building for it. And am working on shelves, desks and such.