Ironman & snakeracing shakles

[L200warrior]

I have in my house a ironman spring 40% load for my car.

Now my doubt is for the part of behind, is better to raise with the shakles that bandage in snakeracing.com or the option of lift block kit but not where to buy this last option.

Someone of two options can give me problems? Which are the advantages and disadvantages of every option?

In what page I can realize the buy?

sorry for my bad english