You won't need the canister filter in a reef tank. It's so much of a detritus trap and so much maintenance that I would never use one outside of minor scrubbing periods (12h-3d max at a time, maybe once a month) with carbon and filter floss.
You don't need a sump, and you don't "need" a protein skimmer, though I would definitely add a good HOB skimmer or in-tank skimmer
For circulation on a tank that size, I would run 3x Hydor Koralia 3G (if you have a lot of rock). I would use 2 if you have an open aquascape. If you look at my profile pic, that is probably just 3 AC Koralias and no issue keeping SPS. It's kind of sad to see that they seem to be basically harder to find. I would get Koralias over no-name DC pumps. LPS coral doesn't like high flow, but I strongly believe your bacterial colonies within your rocks loves it, so you have to be judicious about coral placement.
Again, you can run a small reef happily with just water changes, live rock (cycled dry rock is live rock minus algae/inverts), and flow (that's what I do with my QT). The canister is a distraction IMO. I would much rather throw on an Aquamaxx or Reef Octopus HOB skimmer than a canister filter. That said, I would find a way to run a skimmate collector with my HOB skimmer to avoid reaching around the tank to empty the cup so much. I ran an HOB skimmer 10+ years ago, a Prizm from Red Sea, then a Prizm Pro from Red Sea (much better). I've run a Tunze in-tank nano-skimmer as well - that was never a favorite of mine. In my system, it was probably more helpful for gas exchange more than anything else. It was their smallest model, but it was a very small 30mm cube tank.
I've been through this for a long time, from being a newbie who tried to start a reef with limestone rocks and a bio-wheel HOB filter (like I used to use for Cichlids when I was younger) about 16 years ago, to having a fully automated euro-style 525 liter dream tank today, and many in-between.
