Two of the most recommended tour operators in Louisiana are Honey Island and Cajun Encounters, which offer both plantation and swamp combo tours that can be don in the same day or on separate days. If you just want to do plantation tours, the Laura and Oak Alley plantations can be done in the same tour and both show the interior of the houses.Here is more info on Honey Island http://www.destination360.com/north-america/us/louisiana/new-orleans/honey-island-swamp
The thing I would chime in is that swamp tours on either flat bottom pontoons or air boats. I believe the Honey Island swamp tour with Cajun Encounters is on a flat bottom pontoon.
If you are staying in the French Quarter or there abouts, I would suggest getting the tour company to pick you up (they normally charge around $30) at your hotel or apartment you are staying at. Otherwise, you will need to hire a rental car or taxi and drive there (it takes around 45 minutes).