Here's my 2 cents worth: I started replacing a blown shock and upon further inspection, found that lots of my buhings were trashed. Probably original (15 years old) and needed to be replaced. Replacing worn out bushings will prevent problems with other more expensive things down the line...tires, ball joints, tie rod ends, alignments, etc...

As for OEM bushings vs. the polyurethene type, that's up to you. I chose Energy Suspension bushings more out of convenience because I bought the whole master bushing kit.

If you're a hands-on-guy, you can replace the stock shocks with some nice performance ones and it will still be much cheaper than having a local garage do it.