All Classes in the player's handbook are acceptable, with a few modifications. Psionic classes will be permitted, but your DM is not very familiar with the Psionics handbook, and may alter them a bit once they are more familiar.

Most Official WOTC prestige classes are acceptable, though please speak with the DM about them first. Additionally, the Mythic Races prestige classes will often be acceptable, and you should feel free to develop your own prestige class and consult the DM on it.

Class Modifications:

Ranger: Modified to be the "Monte Cook Revised Ranger", which can be found here:

Druid: Will have a different weapon list as follows: Scimitar, because it is the traditional Druidic weapon; Nonlethal weapons (nets, bolas and weapons that cause subdual damage); Traditional hunting weapons (spears, bows other than crossbows, daggers, clubs including greatclub, and sling including halfling skip-rocks, though you would probably want to take the exotic weapon proficiency in them); and Farming/Woodsman implements (scythes, handaxes, hatchets, sickles, and quarterstaffs). Weapons not on the acceptable list will not result in a total loss of all Druidic spells and abilities for 24 hours, but it will result in a -6 penalty to both attack and damage with that weapon.

Bard: Rumor has it Monte Cook will offer a revamped bard in his next book due out in February, "Book of Eldritch Might II: Songs and Souls of Power", and it is quite likely I will go with that version of the Bard instead of the one in Player's Handbook. If you want to play a Bard before that book is released, just let me know and we can work out something that permits the modification post-release.

Those are the only changes for now, though there may be more in the future.