As much as I respect these guys, their scare tactics are crazy!!

Zone is a great company owned by BDS. I've ran their kits with no issues and you are not cutting any shock mounts. You are cutting the crossmember mounts. Please research from other places as these comments are just funny.
I'm not getting into a b*tch session about this. Research research research.
I will say this Spacers are garbage when used for 3.5 and under, do a proper suspension swap. Spacers used with 4+ are fine and no issues because of how the system is set up. Yes a 4" coilover would be best, but make sure different manufactures items will work together, because not all will.
I would recommend the BDS w/ FOX for 3" or many have had good dealings with Rough Country 3.5 w/ M1 upgrade. If you really want to cut the crossmember, I'd bite the bullet for 6".