Green gaz is in fact Propane, with oil already added, and might smell better than Propane. So Green gaz is already oiled, while with Propane you simply add a few drops of silicone oil, for not even half the price of a GG can.
KSC/KWA are not compatible with KJW (Tokyo Marui clone).
I will leave the upgrades to other users, as I mostly run stock pistols
