Actually... you should not really "tamper" with the URL's - even though there are many people who say that the "nice-names" format for URL's help with SEO.
They don't...
The big search engines PREFER that the dynamic URL is maintained, and with zencart (who constructs very "clean" URL's), the SE's have no problem getting all they need to index and rank your website.
We've just had a situation where a so-called "SEO expert" was hired by one of our clients to get a better google rank, and the guy was given access to the c-Panel and site admin. He set about installing and "experimenting" with a variety of these "SEO URL modules" and all he achieved was the near-total destruction of the site!
It took 4 hours to undo the damage.
If you are intent on having URL re-writing, then please go ahead - and if you are in a business that is competitive to my clients, then I would actually urge you to go ahead... There's a good chance that the damage you may do to your site will result in less competition for us!
