If you plan to drive it a lot, it's currently not set up to do so with ladder bars and leaf springs, and no floater brackets at the axle tubes. The springs will be in a bind with the ladder bars, which is likely why the one side was broken anyway. The other option is a shackle up front to allow the springs to work, and let the axle move rearward as the springs compress. I went the front shackle setup like 4x4's use on mine, as I've done this a couple previous times, and it works.
As for heim ends, I'm not certain when they first saw use, but I use them often. A solid threaded rod end will do the same if you're against the look of heim ends. An adjuster on each tube at the axle end is a very good thing also, as you may find you need to adjust the ladder bar angle once the car is sitting on 4 tires. I've got adjustment on all 3 points, and it's a great help in setting the car up later. Mine are solid adjustable endss at the axle, and heim ends up front.
Might also consider a safety loop around the front attachment bolt point too. If the bolt ever broke the front of a ladder bar will hit the ground and launch the car into the air. NHRA requires them, but I put them on regardless whether I ever run down a NHRA strip or not.
These are mine I built and you can see the tabs up front where my bolt on safety loops go once they're on my car.
Another pic with the safety loops bolted on.
And the bars in place with front shackles angled back to allow spring/axle travel.
