If you want to hear a good southern accent, listen to Walter Goggins. His accent is a really strong southern drawl from Alabama.

Not at all, for southern US think country music ala Garth Brooks, although most of the singers fake their accent. There are some New England dialects that have some similarities to UK English.

There is an accent from the American south that is quite often mistaken for British or Irish: The Ocracoke Hoi Toiders.

Ocracoke is a small island at the southern end of the Outer Banks or North Carolina, it was isolated so long that they maintain a pretty unique accent that outright doesn't sound North American.