When they make plates to stiffen them, it tells me they are good enough for production vehicles but not much more. Are you sure you want to go into uncharted territory and take a chance on winding up weaker than your needs?
It wouldn't be very budget friendly but here is another idea. My plan would be to make replacements out of Moly tube, and some moly plate for the shock mount and outer end. Then all that is needed is somebody that can figure out what will work for equal or greater strength.
If you are still going to run torsion bars, then you are still stuck with a lot of the weight on the inner end anyway, so it wouldn't be on my priority list unless I need to lower the front shock mount for a coilover conversion.