Steve Emerson? He's a pretty solid guy, imo.
His book Jihad in America is the first book I read after 9/11. And he's the first person the FBI contacted the day after 9/11.
He had to literally rent warehouses to hold all the material he'd been collecting for years about the hate being preached in the mosques here. He had a guy go in and tape record stuff in a lot of mosques.