Very common lift to run with 35"s in the US and several have done it and run it over here. Ask Dave for a price on a 4.5" RE Superflex kit but specify 3.5" coils.
Many are swapping out their 4.5"coils in favour of a LCG via the 3.5"s and increased bumpstop.
I have 4.5 RE springs and Currie CA's, had RE CA's previously and the Currie's I would rate higher for durability and wear etc.
I'm on the way to changing out my rear 4.5" coils and replacing them with 3.5"s, only because I am about hack off my rear upper coil mount and install a relocation kit, the kit provide 1" of lift (generally) as the mount is relocated to allow correct coil geometry with lifts over 3.5".
So the 3.5" coils in the rear should make it sit level again......hopefully
And personally even though its the right price for some; I would not purchase any Rugged Ridge items....based on previous quality related experiences.