Here's an efficient disposition of highbars for a calisthenics area. It allows for a full swing or giant on the 9'- and 8'-high bars. You could fling yourself from any of the 6.5'- or 7.5'-high bars to the facing highbar or to the higher bars at right angle to them. The variety of heights accommodates both tall and short people.
From above (floorprint):
Ideally, the horizontal bars should be unpainted and smooth. A rippled bar may increase grip, it will tear the skin off the hands for anyone trying anything but pull-ups. These rippled surfaces were used at Stuy Town and many people have complained to me that they have had to deal with these rip injuries which take weeks to heal. Every time you open the hand, the tear reopens as well.