They both carry an 'N' designate i.e. N107 or the N107c. The N107c being the "comfort" shock, which means it has a lower damping rate than the N107. Probably not a good choice for a Disco. Go with the N107. They will be fine for a ~3" lift for sure. I run a ~5" lift and they still have about 2+"s of droop to work with. Not ideal but still very functional and they ride great. They NEVER top out on the road at high speed (were the most damage can be done to them). Off road, the shocks limit travel with the sways removed, and that's any shock unless you have limiting straps.
Summary, you'll be fine with N107s.