Help adding user comments (reviews) to non-product pages

I'm working on a website that will operate as a "one-stop-shop" for finding camps and activities in the area. My client would like to allow users to leave reviews and I'm a bit stumped as to how to integrate this functionality as they won't be selling anything on the site.

Any advice or plugin suggestions?

(We'll be installing the Universal Search plugin too, if that makes a difference!)