Duncan's Custom makes/provides aluminum cast versions. Their ability to maintain the specs of a gun have been somewhat lacking on occasion. In addition, they've reduced their inventory/availability of guns substantially over the last 6 months or so. You would be unable to add an accessory (such as a laser/light) to any of their guns.
Ring's Blue Guns does a much better job at maintaining specs of the gun, as well as a slightly larger inventory. You can add an accessory to any of their guns.
Blackhawk offers dummy guns, as well as ASP (red guns).
What gun were you looking for?