Considering most high schools don't start until about 8 o'clock, I'd consider moving some of the things that you are spending that hour or two to get ready in to the night before. Make your lunch before you go to bed, set out your clothes for the next day ahead of time, etc.. If you are one of those people who only brush their teeth once a day (which I am most of the time, to be honest), brush them at night. It's the best time to do so according to dentists anyways. All of that should at least buy you some more sleeping time in the morning.
Also 8 hours is good. Personally I find 8.5 helps me wake up a little faster and feel a little more refreshed, though it's really a personal thing. That said don't think that you need significantly less than 8, studies have shown that people ability to tell that they are outputting a degraded performance due to sleep deprivation goes down way faster than their actual performance does, meaning you won't be able to tell if you are suffering from it easily. Other studies have also shown that there are many,
many more people who simply
believe that they don't need 8 hours of sleep than there are people who actually don't need that much.
For the alarm itself, personally I use my cell phone, set it to vibrate + max volume, and then stick it in my pillow case, which I find wakes me up pretty well
. To quote myself from another discussion on the same topic:
The fact that something is rubbing against your face and screaming tends to wake me up nigh instantly.