Hi @edward11 and thanks for your query. Judging by your specifications, it seems you would be best placed to speak directly with Tobii Dynavox which is a business department dedicated to using eye tracking technology for the benefit of disabled users.
Kindly get in touch with the sales team their @ https://www.tobiidynavox.com/ and someone should be able to get back you promptly.
Best of luck with your future project 🙂