As soon as I saw your request for bombast in the gothy realm, I immediately thought of Within Temptation even before I got to that part of your entry. I quite enjoyed their The Heart of Everything album. Lots of bombast, power chords, and gothy cliches to be found here, not to mention chorals, sweeping orchestral bits, and some Latin thrown in for good measure. IT'S SERIOUSLY EPIC. And the singer's voice is lovely, too.