I work for a non-profit where we tackle accessibility issues related to the web, documents, and tech in general. We have a few Vagrant boxes that we use for development and testing, one of them is a Fedora box (GNOME 3 though) that comes with Orca configured [1] so that it doesn't prompt you for setup options. Chrome and Firefox are installed as well. If you have Vagrant and VirtualBox installed you can make use of it like so:
vagrant init inclusivedesign/fedora24 && vagrant up
The box is ~2 GB. This is the repository for the box in question:* https://github.com/idi-ops/packer-fedora
* https://atlas.hashicorp.com/inclusivedesign/boxes/fedora24
We track Fedora releases and update boxes fairly regularly so there should be a Fedora 25 one with Orca once there's an official release upstream.
I hope it can be of use to anyone here. If you have any questions we hang out in #fluid-work on Freenode.
[1] https://github.com/gpii-ops/ansible-gpii-framework/blob/mast...