That's what I purchased, some would say its to harsh of a ride, compared to the rubber. But the polyurethane will last longer. If you go with the polyurethane, put some grease on them prior to installation to reduce squeaks. Here's an article I used when selecting the grease as some can have adverse effects on the bushings:
What grease should you use for polyurethane bushings? The folks at DST tested several options for poly bushing lubrication to see which works best.
www.suspension.com
I went with the prothane grease