If you are using them for a powder ski, then no lift is required. If you are using for your one ski quiver then a little lift wouldn't hurt. I think I have maybe 6mm of lift on my Legend Pros...not really enough to make much of a difference either way. Given that the Gotama is a fairly soft ski I doubt more lift will turn it into a carver.
If you have plans to ski them outside of powder I would recommend some amount of lift (certainly no more than 10mm). The lift will really help putting the ski on edge when you get to snow that is not deep.