Has this already been done? If not, it's not too late to stop it. Source: I've DIY installed a couple doors, I have fixed torsion springs that have snapped, and I used to sell garage doors for a living.
The door is nice. But it's also very expensive. You can get a similar door (steel both sides, insulated, windows) for probably at least 200 less elsewhere.
They're also super, duper easy to install. If you have Torsion springs and you're not an idiot, it's easier yet. If you can read, you've really got it licked.
You basically do 4 things:
1. Line up the door panels/bolt them together (make sure they're level w/shims and then bolt them where instructions say to do so. Easy).
2. Install the track/track hardware on the door.
3. Install the torsion bar/springs/etc.
4. Attach springs/cables to door/wind springs per instructions.
5. Watch your door go up and down.
Even if you've NEVER done it before, don't own a power drill, and aren't handy, you could probably do this with a friend to double check your work in 4 hours. Maybe 5 since it's a 16 footer. This is not a hard job.
This guy gives a great video on how to wind a torsion spring:
http://ddmgaragedoors.com/diy-instructions/replace-garage-door-torsion-springs.php