A 2.0 60' on street tires is good and you can definitely get it. Like mentioned, you slip the clutch. As your car starts to rolls, still slipping the clutch and giving it gas. As soon as the clutch is almost all the way out and you still have traction, gun it. And this will happen fast and once you get the feel for it, it will come easier. I want to say my 05 mustang gt with k&n filter and axle back exhaust ran a 14.0 or 14.1 with a 2.0 60'. I know with a few mods, brenspeed tune and still a 2.0 and it ran low 13's. Later on I got stage 3 cams and with a 1.9 it ran a 12.9. I remember being happy it finally hit 12's.
And if you are going for time, forget reaction time. It could turn green, sit there for a minute and still get a 2.0 60' and run your normal time. Clock doesn't start till you trip that beam. I always let the other car take off first so I can focus on my launch.
If your are asked to race or race a friend, then you want to have the better reaction time. Though try not to spin or miss a shift so that you hopefully win.
But a lot of guys focus on the reaction time and feel the need they have to race the guy beside them. Just remember.
And have fun.