I finally got the monkey-patching method to work by doing the following.
You can add fields to the user class with the method add_to_class instead of inheriting the User class by doing the following in your models.py:
User.add_to_class('new_field', models.BooleanField(default=False))
Once that is done, in admin.py, modify the UserAdmin and add your new field
from django.contrib.auth.admin import UserAdminVoilà, with that done, you're new fields should show up in the auth user on the django admin page.
UserAdmin.list_display += ('new_field',)
UserAdmin.list_filter += ('new_field',)
UserAdmin.fieldsets[1][1]['fields'] = ('first_name','last_name','email','new_field')