Cameron said:If you want the best of both worlds, try the following:
XYZ 6/Rainbow Servant 10
where XYZ is one of the following: Beguiler, Warmage, Dread Necromancer
At level 16, you get everything from both lists, and you have full casting to boot. Sacred Exorcist would even net you Turn Undead (if you are good aligned) or Dread Necromancer would give you Rebuke Undead, which can be used to power DM: Persistent. Either of the above is Cha based, so it synergises with Turn/Rebuke Undead.
Yes, errata clarifies that text overrules the tables making this a very attactive combination once you make it there.