Yes, both a sump and canister. They will work independently of each other. I may or may not use the canister. The sump will be fed by dual Herbie drain system and water returned via a Fluval spring pump also feeding a cow reactor. The fx6 will just have it's plumbing cone over the back.
Now, here is the reason for the canister. We had bought it for the 75g but decided to upgrade to the 180g before installing it. We have horrible water pressure and a python gravel vac barely works. My father saw the Fluval vac attachment somewhere and liked it so that is why we have a canister in this setup. I'm half hoping it doesn't work well so I can eliminate the canister