Gun 1: Benelli M2 12 Gauge
Gun 2: Beretta 682 Sporting with matched 30" .410 and 28 guage barrels
Gun 3: CZ 455 American Combo with .22 LR and .17 HMR barrels
Gun 4: Blaser R8 Professional S with barrels in .223, .270 Win., .300 Weatherby and .375 H&H

That should about do it for long guns. Would need a four more for handguns, though.