Hello!
Okk it seems cool indeed.
I started playing with sorcerer and the difference with a simple mage is awesome (with high charisma, you just blast everything).
I'm now in Chult, and I killed ALL the Yuan-ti with my sorcerer with 3 mirror image, 2 haste, and some mass bombing spells (DBFB, skulltrap, wail, etc..).
My other characters had just to stand back and watch the reptilians suffer to death...whouahouahoua!!!
I personnaly would take a drow and a deep gnome (the special abilities are so cool (Blur, invis., MI, for free onece per day....what could you ask more?)).
Take the drow as sorcerer paladin, and the gnome as dreadmaster would be my advice..
BTW, I would personnaly take a 3rd character (a mage for the scrolls!!!) because the XP difference doesn't hurt so much.
I'll think about it a little more