The name of the campground on Tybee Island is River's End. It is run by the city of Tybee. Their web site says they have WiFi. We camped there back in June, but didn't use the computer, so I don't know how good the signal is. Some of thier sites can be quite close together while others are suitable. Here is a website for them: http://www.cityoftybee.org/Campground.aspx#Amenities
There is another place now called Savannah Oaks (used to be called Bellair Woods) that is about 2 1/2 miles from I-95 and exit 94. We've never stayed there, so I don't know much about them other than what is mentioned at http://www.rvparkreviews.com/regions.../Savannah.html
It does say that they have WiFi. When it was Bellair Woods, it didn't always get good reviews, but I believe that it has changed hands. Their web site is still listed as Bellair Woods. http://www.bellairewoods.com/
The boarding house you are referring to is The Wilkes Boarding house located on West Jones Street. Here is their web site: http://www.mrswilkes.com/
I've lived in Savannah almost all of my life and only went there once, but the food was excellent. We did have to wait in line for well over an hour (or so it seemed). The original owner, Mrs. Wilkes, passed away some years ago, but it is still run by her family. I don't think they are open on weekends. You can look on the web site to see if they have days and times listed.
Here's the web site for The Lady & Sons: http://www.ladyandsons.com/index.php..._of_the_month/
Please tell your wife, that if she's going there in hopes of seeing Paula, most likely she won't. When she first opened up The Lady & Sons, Paula used to be there all the time, but after moving to a bigger place and her popularity grew, her visibility at the restaurant diminished. You might get to see Bobby or Jamie if your lucky, but even they aren't as visible as they used to be. The restaurant is left to be run by her management team. We used to go there a lot in the past, but I don't think the food has as good a quality as it use to have and it's very pricey.
I hope y'all take in some of the historic sites while you are in the area. There is so much to see that my recommendation would be to make the Savannah Visitor's Center and History Museum on MLK Blvd.