16" air shocks are a big wieldy things that are difficult to mount & package on a landrover chassis vehicle, quite simply, there too big,
however a 12" or 14" at a push long airshock in a 2.5" diameter are a better option for a landrover based vehicle,
in regards to your vehicle im trying to work out what your trying to achieve by fitting them,
yes they are tunable for the weight they are carrying, however they need tuning in general for any vehicle, they are not a fit & gas up & of you go system,
i have quite a bit of experience with 2" & 2.5" diameter air shocks & fitting & setting them up on "offroad" vehicles, however for a road going vehicle, there are better options out there