@ReefRob
Keep in mind there are three types of filtration for tanks: Biological filtration, Chemical filtration, and Mechanical filtration.
Carbon, GFO, protein skimming, etc. are chemical filtration.
Bioballs, live rock, etc. are biological filtration.
Sponges, filter floss, etc. are mechanical filtration.
The most important filtration in a reef tank is biological filtration, that is why it is suggested to have a certain amount of rocks in the display tank. Porous rock provides great biological filtration. If you don't have good biological filtration going on, then you will have problems from the beginning.
After that it varies on the other types of filtration that you would like to have. All can be successful as long as you are diligent in keeping up on the maintenance needed for the various types of filtration mechanisms to run properly (e.g. cleaning bioballs and sponges regularly to avoid buildup, pump maintenance on protein skimmers, etc.).
I use carbon and a protein skimmer. I also vacuum the sand w/biweekly water changes. I have a good amount of live rock that I blow off weekly to keep debris from settling in cracks and crevices. And that is it.
Here are some good articles to read up on:
http://www.advancedaquarist.com/2003/2/beginner
http://www.peteducation.com/article.cfm?c=16+2148&aid=2933
http://www.drsfostersmith.com/pic/article.cfm?aid=552