I'd be tempted to:
- switch to non-casting Bards, Paladins and Rangers
- dump the Sorcerer, Wizard, Cleric, Druid
- use the Acolyte and Mage (or Arcanist) advanced classes from d20 Modern
If the setting demands it, create a Druidic class based on the Acolyte, fiddle with the arcane class(es)...