The 8" kit comes with longer brackets, yes. It's also not available as a Class II kit.
I don't recommend the 8" kits at all, the steering is basically impossible to correct properly without building some type of centerlink linkage for it entirely from scratch (it's beyond where you can modify the Superlift Superrunner kits).
If you want more lift than 6", I would use a bodylift. Another option might be SAS, the steering is easier to deal with on a SAS at those heights.
Being that high up is going to also raise your CoG to a point of being impractical for some types of wheeling (unless you swap full-width axles under it).