You planning on keeping your BakPak2 skimmer and just moving it down to the sump?
YOu can then design your sump around that aspect.. Meaning your skimmer in actually NOT inside your sump and you don;t need a seperate section for it... MY HOB
skimmer (remora pro) makes almost ZERO micro-bubbles.. So I was able to design mine without a bubble trap. I do, however, have my skimmer in my Fuge area because the Water level is much higher there then the overflow/return section. It's 100times quieter there