If the bulkhead row is numbered 5, you are on an LUS A321. I've never found row 5 to be too bad, although it's been a while since I've sat there. If you really want legroom take 10A, 10C, or 23F. Probably the best coach seats on that plane.

FWIW, I don't believe AA is flying the newer A321s on LUS routes yet. So, all you'll find on LAX-CLT is ex-US metal for the time being.