Hey Phil,
The plumbing is really just a drain system. It doesn't filter the tanks at all. For filters I use mainly sponge filters in combination with powerhead filters.
Check out this page. I started this thread before I built it.
http://forum.simplydiscus.com/showth...tem&highlight=
Whether or not you want to go with wooden or steal racks is really just a matter of preference. I don't see either affecting this project. If you alreayd have steel racks, I'd go with those since it would save you the time of building your own, of course make sure they can support the weight your going to put on it.