I've heated and bent stock arms on 6 or 7 trucks now and never had a failure. The key is to let them cool slowly. I recomend putting them in a bucket of sand after you bend them and let them cool over night.
I drilled out both arms to 3/4" and ran 3/4" heim joints on both ends of the tie rod, then I welded a heavy duty mount on the pass side of the tie rod, also with a 3/4" hole and bolted the drag link to it. By mounting the drag link to the far side of the tie rod it reduced the amount of angle that the heim had to cycle through.
I also drilled out the steering arm so that all attachment points are via heims. It's easier than having to taper holes for tie rod ends and it's easier to take apart for adjustment or other trail repairs etc.