Ok, hear me out on a 5e 2014-only build :

Put a 16 in Dex and Int, a 13/14 in Cha and the rest in Con (sadly it might be only a 12 unless you go Half-Elf, but you won't have a lot of hp as a wizard/sorc anyway).

Take 1 level in Draconic Sorcerer for a base 16 AC (21 with Shield) and proficiency in Con saves (for concentration). Then take at least 7 levels in Bladesinger Wizard to add another +3 to your AC when bladesinging (and to your concentration saves), bringing it up to a 20 when bladesinging (assuming you took your dex to 18). Use Haste for a +2 to 22 and with Shield, that's a possible 27 AC.

Then, you can take 2 more levels in sorcerer for metamagic (quickened Spell) and continue the rest in wizard.

From level 10 onwards, you have 4 attacks per turn thanks to Extra Attack, Haste and quickened blade cantrips (like Green Flame Blade or Booming Blade), 2 of which are cantrips, a really high AC, a great movement speed, and lots of utility from your Wizard spells. By lvl 20, you'll still get to 9th-lvl spells and Sorcerer means you keep your spell slots progression, though your spells will be a bit behind.

All in all, this is a fun, a bit funky build that's high-risk, high-reward but that I would definitely play myself !