Amber, all I can say is that this will all pass eventually. Why? Because you are doing everything that is right. Just continue with the discipline, time out, etc. There's not much more you can do unless he has a particular interest that means a lot to him - something he wouldn't want to have taken away. With my son, now grown, it was his art. That's all he ever was interested in and it still is.
When he was about 9 he decided to go outside and light a match. It was the absolutely most perfect day for a fire - lots of leaves on the ground, no rain in a long time, a slight breeze. He made a little pile of leaves and decided to set them on fire. Within seconds they just spread like crazy and before he knew it the fire was higher than the top of the garage he was hiding behind. Fortunately for him, he immediately came running in the house for my help. It ended up burning down all our neighbors beautiful shrubbery and it almost set their garage on fire (there was an antique car, their prize possession, in the garage). That was the one time I thought my DH was going to kill one of our children. As punishment we made him use all his money to buy new bushes for the neighbor and help with digging up and planting them. Of course he was also grounded to his room when he wasn't slaving next door and offering them apology after apology. I never saw him light another match since then.
The good news!!! He has grown into a kind, caring man who has never gotten into another lick of trouble in his life. He is hard working and thoughtful and I'm so proud of him. So, keep your chin up and continue exactly what you're doing.