Fusion aren't as good now as they were, in my opinion, but they're decent. I used to have a Fusion 12" sub that kicked like a mule, but it wasn't cheap. Ever since they started selling the Fusion stuff at Repco, I've had my doubts about it. But having said that, they're not a bad brand.
Regarding your install, keep those tweeters in the back near the speakers. If you have components up front then those tweeters will be more than enough.