On my ‘95 Sidekick, I have a 2” spacer and front springs out of a Gen 2 4 cyl 2x4 Tracker. I did some playing, and I put the Tracker spring without spacer on a side and dropped the vehicle off the stands. To my eye, it sat level. And the general info I have seen bears that Gen 2 springs on a Gen 1 yield 2” of lift. I don’t know if there are different spring rates on the Gen 2 for the 4 cyl or V6 models, but I would think you would want to go with 4 cyl springs, and thus not Grand Vitara, but Vitara or Tracker springs.
As far as diff drop...conventional wisdom says not to go over 2” without it. I am over 2”, but also have done nothing but pound pavement since the additional lift. I have the 2” strut spacer. My thought is if you are on stock length struts, you should keep your cv risk lower. The strut is only going to let the control arm droop so much before it is topped out. What you are doing is now you have 2” less suspension drop from your static height. In my experience, that puts your strut pretty close to topped out, which is definitely far from ideal. I have just acquired an XL7, and will probably soon pull the springs out from under it and put them under the Sidekick. It will be interesting to see if there is a difference between them and the 4 cyl Tracker front coils.