How can something that is part of the unibody structure be in the wrong place? Perhaps they have rusted out? If that is the problem you will need a donor car.
The other possible problem I can think of is that you have the control arms on the wrong side of the car, or that you have the wrong control arms for the Duster.
As Grumpus said, the mounts are part of the unibody structure. The car could not have made it out of the factory without them being in the right place and the UCA attached to them. These Mopars are not like the Fox bodied Mustangs.