You can do the buyable ones yourself I think. For the findable ones (which cant be bought):
Sunburst: 150 mana, 350dmg + 10dmg/s over 10s, dropped by Bugbear, Ifrit and the fire monsters (easy to get)
Eruption: 180 mana, 280 aoe damage (shockwave like), dropped by Ungoliant (medium to get)
Teleport: 10 mana, works like teleport scroll, dropped by Succubus and Harpy (maybe F-Harpy and Succubus Queen too) (hard to get)
Storm Walk: 50 mana, blink, dropped by Succubus
Cone of Cold: dont know, aoe damage, dropped by Elmore General (dont know)
Fire Wall: dont know, dont know, I heard its dropped by Ifrit (hard to get)
Burning Weapon: dont know, +8 damage on every attack for 150s, dropped by fire monsters (hard to get)
Greather Haste: 20 mana, +15% move and attack speed for 270s, dropped by F-Harpy and Ettin (medium)
Bravery: 75 mana, +10% attack speed (stacks with haste), dropped by Forgottens and maybe others (medium)
Now the ones of which I think or am sure that they can be bought:
Sleep: Undead, the water monsters in the dungoen
Breath of Earth: Golems
Mana Drain: Forgottens, something else which I dont know
Heal: Undead
Haste: Burning Archer