When I replaced the coil spring isolators on my S10, the new OEM ones from the dealer were an upgraded design made of polyurethane and 3/16"-1/4" thick. The originals were floppy rubber, maybe 1/16" thick, and they squashed and rubbed through. The new ones lifted the front end 1/8"-3/16". Minor lift, but that truck was slammed and tucking the tires so it was noticeable.
Anyway, my point is maybe the OEM ones for yours are similar and/or thicker and you could just double stack another set of stock isolators if that'll lift it where you want it. Or, you could get some of the 1" spacers and cut them down if 1" would be too much lift. Maybe have a machine shop shave them so they'd be perfect if you don't have the means to trim them at home. If it were me, I'd use some scrap plywood to make a jig to hold the spacer. It'd be two squares of plywood stacked. The bottom piece of plywood would have a hole for the smaller diameter of the spacer to sit in, upside-down. The second/top piece of plywood would be whatever thickness I want the spacer to be and would have a hole in it the overall diameter of the spacer. Grind/shave whatever is above that second/top piece of plywood. If the spacer is polyurethane, maybe bring your jig and spacers to someone with a wood planer.
It sounds like a lot, but it's really not. It's about all you can do to make your Tahoe sit just how you want it, though.