Freshwater and Saltwater aquariums whilst undergoing the same process of cycling use different bacteria for nitrification and denitrification.
Really whther or not you would need to start cycling a salt water tank in the same manner as a freshwater tank depends on whether you want a fish only system, fish only with live rock or full reef set up. Live rock acts as the filter obliviating the need for internal or external filters. The bacteria are already present and you only get a mini cycle lasting a week or two. Then you can start to add snails and hermits that will form your clean up crew. A few weeks later and fish can be added.
You may if wanting invertebrates need to empty the tank and fill with Reverse Osmosis water anyway.
I would advise you to read the resource centre in Marine chit chat and look at the stickies in there. Decide what type of system you would like and come back to us if you have any questions or would like to go ahead.
What size is the tank you have.