[Jared]

It'll be really difficult to cut the profile of a gear like this without specialized equipment. That said, you likely don't need a totally custom gear.

I don't think plastic has much of a chance of holding up in a drive application.

Is there a way to modify your design so that it uses bevel gears from McMaster?

If you're doing a large reduction with this gearset, you might consider using a worm gear instead.