Story/book?

So I'm thinking about writing this story that may or may not get really long. Okay, no, it will get really long, I'm just not sure HOW long.
Plot: Band starts, two girls and two guys, kinda friends but not super tight, playing in the garage, all written from the perspective of the female lead singer. Well their guitarist finds them a gig at a local cafe for the summer, and they steadily start getting more and more popular until they become something of local celebrities. As the school year is about to start up again, our main character's senior year, a record guy comes and wants them to be the headliner for an upandcoming indie group and have them record an album. They go on the tour, and as they start to become famous, their drummer and bassist up and quit. The bassist got preggers by a groupie she slept with and the drummer didn't want to get famous, he just wanted to fuck around and play instruments. Well their manager says she can go solo, or she can end it all. If she goes solo, he'll get the guitarist set up with a different band. She goes solo.

Main character:
Name: Penelope Nash.
DOB: 9/27/93
Hair Color: Dark brown with purple bangs.
Eye color: the left eye is dark brown, the right eye is light blue.
Height: 5'7
Weight: 135 lbs.

Guitarist:
Name: Derrick Grafton
DOB: 5/10/92
Hair Color: (naturally) Blond. (dyed) bright green.
Eye Color: Bright Blue
Height: 6'5
Weight: 162 lbs.

Bassist:
Name: Rita Joesph
DOB: 10/10/94
Hair Color: Bright Red
Eye Color: Green
Height: 5'2
Weight: 134 lbs.

Drummer:
Name: Joshua Jennings
DOB: 8/5/93
Hair Color: Black
Eye Color: Greenish Blue
Height: 5'10
Weight: 123 lbs.