So I just came back to DDO a few days ago after being gone for about 2.5 years. I leveled my main character up to 20 (he was level 14 when I came back), so now I am sitting on a level 20 pure sorcerer. I want to do epic levels this time around so I am looking for the easiest and most powerful way to do that.

A few things to keep in mind, I am a pure sorcerer, so no multiclassing. Let's assume I don't have high DC's at anything (I found a few high DC builds). I have access to all the heroic past life feats except for sorcerer and warlock (this is my 13th life). And lets assume I don't have any super gear. What are the best primary/secondary element for the 20 heroic levels of my sorcerer and what is the best epic destiny and twists for the epic levels? What feats are most important for me to take?

Currently I am fire/earth, but I am guessing I should switch to air since knockdown immunity seems pretty important (though I am open to absolutely any elemental builds). I assume I need to focus on spells that cannot be evaded or else low DC's would cause a problem. I would love to be able to solo epic elites, but I understand if that isn't possible with such a character. I will settle for whatever power I can get.

Thanks for the help.