I listened to the songs, very good.
One thing is probably certain, early Johnny Cash is Rockabilly, or close to it, I think I even had some old Sun album stating that. It's like all music, maybe not that easy to define a genre, a style of music.
Of course, Johnny Burnette, early Johnny Burnette that is for his short life:
http://www.youtube.com/watch?v=Uv1xvMjxqcQAnd then, he went out to Hollywood and sold some songs to Rick Nelson.
So, it's wide open, Rebel Rouser by Duane Eddy might be another example.