Those would be the right guys todo it as they wrote APF/BFD, I personally would suggest installing interworx first, and then letting them do their hardening.
On their web site it doesn’t say InterWorx under the supported appliances area at the bottom. I would suggest e-mailing them first before you go anywhere with it.
The RFX-networks guys themselves use IWorx-CP so they will probably be able to help you out even if it’s not listed, but as Kyle said I’d definitely email them to confirm.