I've got a 2000 GV with the about 60,000 CALMINI lift miles on it. Two words, LOVE IT!
I helped a friend with the OME kit from RRO. It rode very rough, could not get the camber within spec and wasn't quite 2" of lift. He ended up removing it about 1 month later and replaced it all with the CALMINI system.
My recommendation is the CALMINI 2.5" system (notice I say "system" and not "lift", as it really is comprehensive and well engineered). You will be much happier spending the few extra bucks in the lond run. Properly lifting an IFS truck, especially the GV, is a lot more than some longer struts/shocks and springs. For instance, how do the others correct the issue with the tie rods on the rack&pinion steering? CALMINI included the extensions so steering isn't goofy? The others? CALMINI includes diff drop brackets and redesigned control arms to ensure that the CV joints remain within the proper range of operability. The others?
Go CALMINI and you'll be happy you did.