Coil/Springs and Upper Control Arm Ball Joints

Hi- recently started ripping next project car- an '82 928 
Any assistance on finding aftermarket coils for front and rear suspension is appreciated.
Mine appear to be original- i dont have an instrument to test the compression resistance, but presume at 44 years old, the steel has been compromised
I'm not restoring to factory OEM specs, so i presume coil overs might be in it's immediate path
similar question for front upper control arms- bushings I found no problem from vendors like pelican parts and FCP Euro, however no luck searching around for the ball joints
one of the simplest suspensions to work on- 3 different size bolt heads, mostly aluminum parts so no torching needed and boy oh boy, they were miles ahead of the detroit line up for suspension geometry in the late 70's 
thanks for your advice in advance 

update on the front upper control arm ball joint
928motorsports sells a rebuild kit so the upper wishbone/a arm can be salvaged 
(just dont throw away the existing ball joint....)
928motorsports.com/product/ball-joint-rebuild-kit-v/

For the ball joints, I think you'll likely need to source the complete upper control arms since the ball joints aren't usually sold separately for the 928

Check 928 Motorsports or Lindsey Racing , or even carid they may stock them for older models like 928 but not sure.

For the springs, H&R and Eibach made lowering springs for these, or you could even go the coilover route with something like KW or Bilstein setups

thanks Uncle Branton
the ball joint repair kit worked well for the front upper wish/control arms.
was able to replace all bushings and the ball joints while salvaging the control arms
yeah i went the coil over route w/ the 4 springs/shocks, have adjustable damper control so will see how she feels once it's all put back together 
Jason