Yeah, I was thinking about vertical space as well. I think I have plenty, but I suppose the lower it "sags" the more arched your back is while sleeping?
If I can do it in a 2dr Jeep, I am confident you can do it in a Suburban. You will just need to drill some holes in the trim, put some nutserts in, and add a pair of eye bolts to hang from.
I have used a hammock in my Nissan NV (tall van) but the only way to get the angles for comfy sleeping is to go from D/S back corner to P/S front "A" pillar.