I haven't heard of JS-Kit before.
I just did a quick search for it and found http://lifehacker.com/software.....218219.php
Based on that it sounds like a bad idea for a business web site for the following reasons:
1. The comments are stored on http://js-kit.com/ so if that site goes down so do your comments.
2. It uses Javascript which like flash should be avoided unless absolutely needed to let your site functions be usable be the widest audience possible.
It does the have the advantage though of being easy to implement.
You just add the JavaScript code listed at the top of the page http://js-kit.com/reviews/ and you have comments.
If the above two reasons don't look like a problem for your site you can just add the code on that page and be done.
Otherwise if those would be problems, post what server side language you use (ASP, PHP, Ruby, etc.) and I can see if I can find a comment system that would work.
Note though as far server site languages go I only a little bit of PHP so I can't help much for other languages.