Is the a aftermarket bed cover available for these? Or what is everyone doing for a bed cover besides a tarp?

Is the a aftermarket bed cover available for these? Or what is everyone doing for a bed cover besides a tarp?

Dkf lab
Makes one not sure where they ship to
I'm making my first one out of wood with lifter arms so I can mount a spare to it
An will eventually make a fibreglass or aluminum one

This is the dkf one

Here's mine