Filtration on 36 Gallon Bow Front

I currently have a 36 gallon bow front that is set up for freshwater. I'm thinking about converting it to a saltwater. My question is around filtration. What should I use? I had read in another post that someone used a canister filter. My lfs recommended that as well. Is the live rock enough as long as a I have a couple of power heads? I will probably get a skimmer down the road but do I really need one right now?

Sorry for the redundant questions but there is a lot of conflicting info out there.