That's the problem with lowering or lifting, you always want more! At least that's always been my experience.
I'm going to order the 2/3 from GF and see where it sits. Maybe cut a little off the rear springs if I have to in order to get it level. Further down the road I am going to replace the rear springs with the ridetech coolride bags. Then I can get the back where I want it at ride height, air it out when I'm parked, and get a better ride out back. I'm thinking ridetch shockwaves for the front eventually too, then I'll be on air at all for corners. We shall see.