There is a member here with the full kit, unfortunately it's very hard to get a full kit, or even a 2 barrel set. The full kit, due to the short barrel and pistol grip, should probably be registered, although it's a bit of a gray area. Remington LE doesn't want civilians to have these, and the USDOS is unpredictable with regards to letting them leave the US. If you were to buy an 18 inch version, I'm sure with some modification, a 14 inch tube could be made to work. The MCS uses different lengths for the barrel ring, so you can't use a regular short 870 tube on an MCS, and you can't can't use a regular 870 foregrip on an MCS either.