I understand your concerns. Although you need to do something and do it fast, boot camp is very drastic. Although the teen boot camp experience does work for some kids, other just get even angrier because they feel like their parents don't want to deal with them and they feel abandoned.
A viable alternative to boot camp is a program called The Total Transformation. It's a behavioral program that you can use at home to teach your son how to cope with his anger, how to make healthy choices, treat others with respect and do his job at home and at school.
Although working with him may seem impossible because you have tried so many things in the past, this program will teach you simple techniques that you can use right away. Best of all, it teaches your child life skills. As he makes the right choices and starts to feel good about himself, this behavior builds on itself so that your teen will want to continue making the right choices. It really is an effective program and is not expensive, especially when you consider the cost of teen boot camp.
Since you are conflicted and are looking for an alternative to boot camp, I think you should give it a try. This Total Transformation review will give you more information. Good luck.