Anyone of the 911 years from '71 on will work but try to find something as new as possible. Try and get the whole thing including the steering rack if you can and just change the complete package out. Also replace all your rubber a-arm bushings out with the "poly-graphite" by weltmeister if you never want to worry about those again. Upgrade to 930 turbo tie-rods and also do the bump steer kit on the front. Pelican should have all this stuff.
On the rear try Brad at:
http://www.all914.com
I know He and Rich have some 914/6 hubs in their stock. With the V8 engine you may want to upgrade to the 911 rear hubs and stubs with a larger spline, larger CV, and bascially just beefier!... Brad and Rich also have those, if not I do have a set I may be willing to part with.