Two ideas for level split.

Warforged....

Favored Soul 6/Wizard 14

OR....

Favored Soul 2 /Wizard 18.

16 STR
8 DEX
15 CON
17 INT
6 WIS
10 CHA

You're basically taking the favored soul for the great sword feats, and limited buff casting, as well as wand use.

Wizard Pale Master 2 and lich and maybe wraith form.

Taking Inflict serious wounds as your third level spell means instant healing in undead forms as well as healing of your minions. Enough Wizard levels to land FoD and wail of the banshee reliably. BUT... is the initial benefits of the favored soul worth giving up for the higher level wizard spell slots?

You pump up UMD, and you can even start scrolling higher level divine spells.