I doubt if it would end up lighter than a normal Hotchkiss leaf spring arrangement by the time all is said and done - including whatever you have to do at the fixed end of the springs to absorb that moment load. If you are stuck with a live rear axle it's hard to get lighter than Hotchkiss leaf springs because the same elements do the springing and the axle-locating, and they do a decent job of spreading applied loads out around the chassis instead of applying them in concentrated locations that then have to be beefed up. Of course, there are side effects, e.g. axle wrap-up, and imprecise side-to-side location.
Among the production live-rear-axle setups that I know of, the one that has the best geometry is that used in the S197 Mustang - 3-link with panhard rod, coil springs. The roll center is not too high, they can have decent anti-squat, bump-steer and roll-steer behaviour is not bad, axle wrap is well controlled, there's no binding within reason.