Ipads for People with Visual Impairments?

I received this question. Anyone have any answers/ideas?

We have been discussing in our church accommodations for members with visual impairments for whom the projected words at the front of church are difficult to read. The idea has been proposed of purchasing ipads that mirror what is on the projection screen, to be distributed to those who have such difficulties during the service. This idea is still in the beginning stages of planning, and nothing definite has been implemented as of yet, but we wanted to reach out to the Office of Disability Concerns and see whether you had any advice or guidance on this issue.

Are there any other churches that have adopted this solution? What are its benefits and challenges? In churches where this has been implemented, what has been the response? Are there cheaper alternatives to ipads? Are they as user-friendly? Are there any other questions we should be asking as we contemplate this approach to this issue?