+1 for a skimmer. If you don't have space inside your DIY wet/dry for a skimmer, then get a HOB
skimmer. Purigen does a similar job to a skimmer, but on a lesser scale.
you do not need the wet/dry filter since you have the rocks in your tank. They both do the same thing, but the live rocks are more efficient. Having both is fine though. I would replace the wet/dry with a sump.