i've got Gmax shocks and springs

i know,,, on my mk 4 golf. only for looks purpose so didn't want to spend too much.
i want to lower it more. will only gmax springs go on the shocks or can i put diifferent make springs on? dont think gmax do a 45mm drop so i need to find different ones.
shocks are only one years old so dont need new ones.
thanx