First off, welcome!
I just went through this process, and the best advice I can give you is buy a wider tank than a 55 gallon, they are too narrow. For a reef, you will want/need a sump or a refugium, and the commercially available ones are too wide to fit in a 55 gallon stand. Don't run a canister filter, it can be done, but they need to be cleaned weekly in order to keep them from filling with bio matter that breaks down into nitrates, a no no with corals. Another strike against a 55 is that they are too narrow for quite a few species of fish to turn around comfortably in. I recommend a tank 18" wide at a minimum.
Get a 75 gallon, much better.