I thought about that, too: Introduce Planetouched, Drow, Duergar, Svirfneblin, and all the other stronger PC Races as quasi- MonsterClasses - except, you'll get to combine that with the class they're going to do first, and keep their normal favored class (no "Drow" as favored class.).
Maybe at 1st level they are like a member of their "standard race", and instead of leveling up as class, they level up as race over the next levels, gaining the races special powers:
Example: Drow Fighter.
1st Level: Treat as Elven Fighter 1 with PHB Elf Traits except Automatic Languages like Drow, +2 Int instead of Dex and now low-light vision, plus light blindness, Darkvision 60', +2 racial bonus on Will saves against spells and spell-like abilities.
2nd Level: as above, plus Darkvision 90', +2 Dex, Spell-like abilities.
3rd Level: as above, plus Darkvision 120', +2 Cha, Spell resistence.
(4th Level: advance as class, with skill points, better saves, better BAB, and so on)