I live on Johns Island and have Comcast, which is what most folks out here use. The office is in a little strip mall on Maybank Hwy(next to Kerr Drug at River Rd./Maybank intersection), where there is also The Hickory Hawg (great little B-BQue place),Maria's Mexican Restaurant (also good), and Rhonda's Hair Salon.
The Comcast service used to be terrible and was always going out for sometimes a day or two at a time, but last year they updated it and now we have no problems - except for a price increase.
Welcome to Johns Island!