Fabtech and the others would be an excellent place to start. Give them a call and see if you can order just the front end for the 73+ trucks! Since the front suspensions are pretty much the same. Remember that you have drums up front, and discs were factory starting in 71. This gives you the perfect reason to swap to discs!!!
You may be able to keep your drums if the $$$ doesn't work for you, but I don't know if the ball joint problem will be easily fixed
Good luck with the install...