I'm not quite sure what tack we're going for here, but I think I have it down enough to suggest that you seek out music by Wuthering Heights, Demons and Wizards, Dark Moor, Turisas, Ensiferum, Secret Sphere, Star One, late Therion, and possibly Wizard and Domine. A bit either side of what you're talking about, but it's a narrow gap (basically, power bands with keys, almost).
Of course, the obvious one to mention is Nightwish's early material, but I'll probably be shouted at. Nowt wrong with Angels Fall First though.
And of course, I'm pretty keen on this kinda stuff, though I always thought Sonata Arctica were terribly over-rated.