Really the best filtering for a sw system is the bacteria that lives in the rock. After that, a protein skimmer is nice. You don't need a bunch of ugly machines hanging off your tank, and the ones that are built to trap dirt like filter pads can backfire: by forcing the bacteria to work on the poop there, instead of in the rocks and sand, they unbalance the chemistry and raise nitrates. That can be upsetting for coral.
I find it helpful to use a gravel vacuum to suck out the poop every week, and a turkey baster or power head to blow stuff off the rocks before I change my water. But besides that the tank pretty much takes care of itself. It's cool like that.
Why do you think you need more filtering?