Yes, torque boxes be a good addition to a regular, driver type car. They tie in the rocker panels to the sub-frames which helps solidify the whole structure. The rocker panels are very large, rigid structures ina mopar. That is why they were added to Hemi cars and convertibles.
Subframe connectors will accomplish a similar thing in a slightly differing way. They tie the sub-frame connectors connectors together and, depending on what type you use, also tie the floor pan in with the sub frames.
As far as which one is better and provides more support, I don't know. I can tell you either one will firm up the car and allow the suspension to work better as well as eliminating some creaks, groans, and rattles in the car overall.