71 C20 saggy suspension

[elJefe]

I have a 71 C20 burb and it seems to have the original springs which are sagged out and bouncy like crazy. I also have 20" wheels with too much offset that were installed by the previous owner. The wheels offset causes the tire to impact the fender on bumps or when more than 2 people are in the car. I think that I should revamp the suspension first with new coil springs and address the wheels after. What do you guys think? I would like to return the truck to stock height and was wondering who to buy the springs from and what shocks to purchase for the 3/4 ton chassis. I bought some rear shocks from cpp but i think those have blown cause of the saggy springs.