Port City Java is a good place to use wifi. They have them all over town.
As far as light jazz goes... I don't know of any. WHQR, 91.3 plays some classical music, and I suspect they might have jazz at certain times.
Cape Fear Jazz Asscociation, wilmington north carolina
Might find some good info there. I think there is a pretty decent selection of live light jazz in the area. I listen to some jazz fusion type stuff, and I hear very little of that.