That sounds awesome!!!We have the standard gage (whatever Lowe's sells) chicken wire for the run and then an inside roosting/nesting area constructed out of plywood...where the hens sleep. Never had a problem with anything breaking in.
BUT - we have a lost a bird or two in our free range flock from raccoons. The chickens roost up in the rafters of the building, but if anyone roosts low, they were fair game for attack. We installed an alert system (those wireless alerts that notify you someone is in your driveway) and pointed it up the mountain, away from the chickens. If anything walks past the unit, an alarm sounds in the house.
Yes, that means we have gotten up at 3 AM many nights to chase critters through the woods...but, we haven't lost another chicken (knock on wood) since installing it.