i think it wound just be easier to make up (to me).
i thinking of drilling and tapping the bottem and just simply screwing in a rose joint.
to make a bush would require mabey machining up custom poly bushes
also might have to weld on a seperate mount to suit a soft bush. id like to keep it simple and easy and avoid welding to much
also keep in mind my car is track only. vibrations dont worry me toooo much.