I think the rubber pads would be worth a shot, but really what you would like to do is also drill the holes a little oversize and bush the bolts, so that there isn't any metal on metal. Alternatively you could disassemble the urethane from the existing mounts and replace that with rubber, although I'm not sure where you'd get the right rubber for the job; McMaster Carr maybe?
By the way, here's a photo of a torque strap that you asked for. One bracket welded to the frame, the other bolted to the engine in some secure location, and a couple of rod ends connecting them together: