I'm not sure why you would want to take a backward step on suspension but, a Panard rod is plenty strong. A 1" .094 wall tube, Panard rod, will take a lot of abuse, if it's well made and easy to adjust with L&R threads. Put 3/4" rod ends in it. Remember to install it level, with strong brackets. Rock climbing, you might want a 1 1/4" x 1/8 wall tube.
The radius rods are plenty strong, too but, make sure you use the later or after market bushings to the frame or it might tend to "wander". The originals had to much for/aft movement.