I will always recommend fill fenders with metal stays, but I am in the PNW.
If you do go with full fenders, I highly recommend that you “pre-bend” all of your stays. That is key to a solid installation. There should be no “spring” (elastic deformation) when you attach or detach the fenders, or they will be more apt to vibrate, rattle, and go out of adjustment, as well as posing a bigger risk of catching on a tire and making the rest of your day very unpleasant.