yup skimmer with the drain in/fuge/return
also with your skimmer so close your return you are likely to pick up some bubbles, always try to keep the skimmer as far away from the return as you can to cut out the bubbles going threw the pump and im sure you know why
witht he way i said you can have a bigger fuge also sence you can do away with one chamber
on the return pump if your tring to make the fuge as big as possibul then it dosent have to run the full width of the side of the sump, can make it fit the pump fairly close