https://www.oldmoparts.com/parts-service-brakes.aspxOr have your old ones relined, plenty of those services listed in the internet, I have no experience with any of them though.
Some of those disc brake kits are poorly thought out, any that require heating and bending of steering arms are on my nope list as are any that use an aluminum hub.
You 58's front suspension is completely different than my 51's so my solution will not directly apply, which is to use OEM stuff to convert to discs using my own mounting bracket design. Still in development right now, waiting till100+ degree days aren't in the forecast.
One other thing to think about, years ago I put discs on my 64 300. Essentially, I measured things out, went to the boneyard and found a later Mopar disc setup that would work, spindle and all. In my case the late B/F/M/J/R spindle was the same height and could be made to work if I used the newer steering arm and trimmed the tierod assembly from the 64, but that was back it the 90's and the details are fuzzy anymore. A later dual reservoir 4 bolt master cylinder and the prop valve form the brake donor were used as well. I want to say I used a 79 Cordoba as the donor for everything but the master cylinder and the hard lines.