Faiths and Pantheons describes the four elemental deities (Kossuth, Grumbar, Istishia, Akadi) and stats out one of them. (Kossuth, deity of fire)
They are all Greater deities.
So in Faerun, its certainly possible to draw power from elemental deities.
Dragon 347 has stats for Princes of Elemental Evil, 353 has stats for Princes of Elemental Good- or you could make your own.