Chainlink to keep out predators, small chicken wire around the bottom to keep small chickens from getting out and coons and possums from reaching in. old fence laid flat on the ground around the outside and wired to the fence, with some heavy rocks on it to keep diggers from digging. Small run, wire on top, great big run, String fishing line to deter hawks and owls. Added protection, electric fence, run six inches, eighteen inches, four and six feet from the ground around the outside.
Coop floor, my personal preference is dirt with deep litter, clean out about once a year. If you are going to do DL you could just put an inch or so of dirt or compost on top of the concrete. You will probably have to sprinkle the litter once in awhile so it can actually compost and not just dehydrate.
I would not add a wood floor over the concrete, too easy for rats and mice to setup housekeeping under there.