Symphonic Rock (is that the genre)

[Invisible]

What would you say the genre is of

KISS - "Symphony"

Metallica - "S&M"

Nightwish - "Once" - "Dark Passion Play" - "Imaginaerum"

I am looking to find more music of this variety. Any pointers?

[fender]

Try here as this may help you - http://www.progarchives.com/

[Rockulus]

There is an abundance of bands similar to Nightwish, although arguably Nightwish are considered the best.

Within Temptation ("The Heart Of Everything"), Delain ("We Are The Others"), Imperia ("Secret Passion"), the former lead singer who left Nightwish called Tarja Turunen ("My Winter Storm"), Xandria ("Neverworlds End"), We Are The Fallen ("Tear Down The World") & Elysion ("Silent Scream")... Happy hunting, hope these offer something of suitable interest. :O)

[Tuoni]

Sinergy Alexi Laiho other band I have heard good things about them, Marco Hietala plays on a couple of their records too.