Around here it's "a gentleman and a scholar."

If Robert Burns is the original popularizer of this expression, as ASp has so usefully pointed out, then the British influence in the original Thirteen Colonies might explain why "a gentleman and a scholar" is more familiar in Faldage's hereabouts than it is elsewhere in America.

It would seem likely that the hero of the Battle of Gettysburg [at least in the North], General A. S. Webb, popularized the variant "a scholar and a gentleman".

It reminds me of John F. Kennedy's use of Gandhi's aphorism "Ask not what your country can do for you ...". No doubt, if there is any variation between the two aphorisms, JFK's variation will prevail in America [if not throughout the world, considering his trail-blazing mastery of the new media of television].