Skimmer and return should not be in the same section of the sump. The Inlet section of the pump should house the skimmer, with a bubble trap to follow. Water levels for the skimmer need to be constant otherwise, skimmer output will be inconsistant and ultimately, less effective. The return section of the sump is where you'll view your evap, so the water level in that section will fluxuate daily (unless you employ an ATO unit). Additionally, Microbubbles from the Skimmer should be trapped out before they reach the return pump. You should not be generating any bubbles in the Refugium section, so the need for a second bubble trap is absent.
One final note, You do not want a Skimmer to follow your Refugium in the sump, otherwise, you will inevitably skim out some of the natural food source you are generating in the Refugium.
Suicidemonkey, Here is what you want. And yes, you should make your own. much more cost effective, and you can employ a better skimmer than come with the wet/dry contraptions they sell.
20 gallon sump with refugium before, and during operation.