Sorry for the delayed response, I have been on vacation the past week and half. Depending on what is important to you, I would go with the Navionics Platinum South($199) or the Nav+ Regions south card($149).
The major differences between the two are the Platinum card has google overlay and 3D capabilities, but if those two features are not important to you, then I would go with the Regions card. It is the exact same Nautical data including the Sonar Chart layer(on both cards), it just does not have the 2 features I mentioned above, which some anglers do not use and can save the $50.
First I would take a look at the Webapp on the Navionics website for free and compare it to any other mapping you are considering to make the best choice for you and where you fish. http://webapp.navionics.com/#boating