@OP: sweet video.
In the video you say that the only way to obtain the restoration spells is by doing the dawnguard side. Is this true? There is nowhere to find these spells in the game, no dungeon, random loot, anything like that? Maybe even killing the dawnguard members?
I want to do the vampire side, but my vamp Mage needs those spells......
And what does more damage to a vampire, a sunfire spell or firebolt. The both do 20 or 25 damage, but vampires are weak to fire(not sure about sun but I would assume so) so my thinking is that firebolt does more damage to vamps but I am not certain of this.
Thanks man.

Zero other ways to obtain the spells, unfortunately. :\
But yeah, I would assume firebolt is better due to the fact that it also does a bit of damage over time, where sunfire doesn't cause that effect. Really, if you have access to the destruction variants of the spells, you should just use those as they're better.