Ok, finally sitting here with my d20 Modern rulebook.
I've noticed that the Occultist advanced class....well basically sucks. Instead of spells, they get 2-3 single-use scrolls as each level, incredibly weak SR (5 + adv class level), a shadow contact (for informational purposes only), a bound shadow creature that might be nice except it's 2 HD, the occasional free magic item, and at 10th level, their big uber-ability is that they can spend an action point to banish a shadow creature who get a bonus equal to its HD to the save.
Would you allow me to use the Mage from Urban Arcana instead? It's pretty comparable to a wizard, except that it only goes up to 5th level spells (keep in mind, it's an AdvC, so I'd get 3rd level spells max), and the spell selection is very limited. They get a few extra item creation feats to compensate for this.
Up to you, I'll settle for whatever you decide.
One more thing: as this will be taking place during the Great Depression, are there any measures we need to take regarding equipment and wealth or will that be provided for us?