Just razzin' ya'.
The stickshift and nitrous, although being more fun (for me) are also done in the name of streetability.
The nitrous allows a person to build a mid 10 second car that is fairly 'mild', runs on pump gas and offers a much longer service life... compared to a n/a 10 second mustang.
The stickshift allows the car to run the street without a loose 8" converter... and still go quick at the track.
The car can run all over town n/a on pump gas, and still smoke the crap out of the tires as much as a person wants using radials.... but replace the fuel with race gas, turn the valve on, and add slicks... and it's GO TIME!
Fun on the street and fun on the track.
Automatics, however, are easier to get to work on the starting line, and tend to be easier on the drivetrain.
Good Luck!