Memorizing all the Murphy bios might give you a little more info that reading just one. Regurgitating his bio word-for-word won't get it for you at a "real" SAMC board. His bio is standard reading for canidates; it's a given.
To set yourself off as an "Audie Murphy", I suggest you read his autobiography, To Hell and Back" or find a copy of COL(R) Harold Simpson's Audie Murphy: American Hero. You could also visit audiemurphy.com, the largest web site dedicated to all things Audie Murphy. If it were up to me, reading To Hell and Back would be required reading for every NCO.
In other words, my friend, don't memorize Audie, get to know him. He was much more than just a soldier. Like I said earlier a real SAMC board might ask you: How many children total were born to Audie's parents? How much did Audie weight when the Army finally accepted him? What city and what building did Audie enlist in? What U.S. Army Infantryman's weapon was Audie holding when a mortar round blew up between his legs?...Was this Audie's 1st, 2nd, or 3rd Purple Heart?...Who else was near him when this event took place?...What was the status of the other soldiers? Did Audie Murphy ever steal a jeep to return to the front lines? What kind of weapon did Audie use when he wiped out German machine gun nests after his best friend PVT Lattie Tipton was killed? After leaving Active Duty, how did Audie ween himself off painkillers? Name all the enlisted and officer ranks Audie Murphy went thru...
See what I mean? All or any of those online bios won't provide you with these answers.
Other than that, best of luck!