I dont believe anyone sells the stock rubber bushings alone. The dealer sells the upgraded unit which includes the ENTIRE swaybar with bushings attached to the bar.
I went with the poly replacements about 2 years ago, and recently began to hear some mild clunking over on the passenger side. Havent had a chance to get up under there and check it out yet. Could be that I didnt torque one of the bolts down fully. Its a TIGHT fit to get to the rearmost bolt on the passenger side. That said, I did notice a slight increase in harshness coming through the steering wheel on very rough and rutted roads that I didnt feel with the stock rubber bushings. I have not had any creaking or squeaking noises though with the poly