The top photograph is not Buford's staff. It was taken at Falmouth during the winter of 1862-1863, when Buford was the Army of the Potomac's chief of cavalry. He is pictured with other staff officers.
The bottom photo is false and doctored. The officer on the far left, Capt. Joseph O'Keeffe, was captured at Brandy Station during the attack on Yew Ridge during the afternoon phase of the battle, and was not present when this image was taken in August or September 1863. He had not yet been exchanged. An undoctored version of the photo--without O'Keeffe inserted into it--exists.
From left to right: O'Keeffe (again, not present), Capt. Myles W. Keogh, Capt. Peter Penn-Gaskell (a direct, linear descendant of William Penn), Capt. Craig Wadsworth (nephew of Gen. James Wadsworth, who had served on the staff of John F. Reynolds), and Lt. Albert P. Morrow. We know that this image is post-Gettysburg, because Wadsworth and Morrow both joined Buford's staff AFTER the Battle of Gettysburg.
As a young man, Morrow had movie-star good looks. Keogh described him in a letter to his brother as being "the devil among the ladies."

Keogh, of course, was KIA at the Little Big Horn. Morrow remained in the Regular Army and retired a full colonel. For a biographical sketch of Morrow, see:
http://civilwarcavalry.com/?p=117