We have a nice, perfomance oriented 3-Link rear solution for your car. I have a 70 Camaro in my shop at this time getting a mini-tub job and full rear suspension install (and some other goodies too), there are some progress pics on the site. You can also see my own 70 Camaro project. I am sure there are other options out there, but this setup is ready to go.
Best of luck with your project,
Mark
www.lateral-dynamics.com