Looking For Rear Springs For 87 Gn

[the wrath]

i have a 87 gn that i am looking for springs i went to autozone they have varaible rate rear springs they make the car sit up to high in the rear i hate that look i want factory height oh i have a heavy sound system in it too 4 10 inch subwoofers and 2 amps i need some heavy duty rear springs please help