SEO-friendly URLs

This post could probably go in the miscellaneous section. I am developing a directory website to service churches and religious organizations and am beginning to think about SEO and url creation.

The search results page url looks like this: www.site.com/profile/search?search=books

Each profile listing gets its own page, and I want the page url to be more user and seo friendly. I’m thinking about something like this:

www.site.com/organization-type/organization-name-city-state

or

www.site.com/organization-type/city-state/organization-name

I want to try to avoid having the profile id in the url, but recognize that including it would be the most full-proof way of avoiding any problems down the road with similar or duplicate organization names. My question is, should I go ahead and add the id in or keep it as above and use the org name, city, and state for the query parameters? Also, should I tack .html onto the end?

I have read some about mod_rewrite for url rewriting, but it seems like Yii url manager handles the rewriting just fine. Are there any performance or other advantages with one vs. the other?

Thanks for any insights.