Here is a review of one brand I found, you might some others. http://www.reefkeeping.com/issues/2007-12/pr/index.php
The setup on each are similar though they can vary slightly. As far as fine tuning one, you would have to choose the reactor model then learn to fine tune that one. There are a ton of different brands and models. MyReef Creations, GEO are a couple of popular brands.
