Oh first of all, I just found out Pathfinder point buy is not the same as 3.5. So according to Pathfinder, you will be using 25 point buy.
@Raineh Daze: Looks like if you kill Shar you would take on the Undead Qualities salient divine ability. I would suggest a slightly different build, but the one you present is perfectly acceptable.
Sorcerer 28/Incantatrix 10/Cleric 7/Walker in the Waste 10
If you give yourself 2 more levels of cleric, you would be able to cast epic arcane and divine spells. In reality, though, I would probably change your build even more.
Sorcerer 18/Incantatrix 10/Cleric 17/Walker in the Waste 10
If you give yourself 17 levels of cleric, then you qualify for the Undead Mastery salient divine ability, which you may want. Concerning which deity you would worship, you know you can choose an ideal in 3rd edition just like you can in Pathfinder? In fact, while I agree with you it can be just a kind of easy way out, in cases like this it may be preferable. I would rather you pick an ideal than a god that didn't fit the flavor. And once you become a god, your divine spellcasting will come from yourself anyway. If you do pick a god, then once you become a god we'll want to describe your new relationship with that deity as probably a subservient deity. At the very least, you would be an unwavering ally.