There is no official checklist for what the plain language disclosure must include; you will find significant variations among the disclosures produced by forms vendors. The closest you will come to a model disclosure on this subject is IRS Publication
590 and the current version is for the 2005 tax year; i.e. it does not contain recent changes.
I suggest that the plain language disclosure should be as current as possible at the time it is distributed. Nevertheless, distribution of the current Publication 590 constitutes distribution of the required disclosure - there is no specific requirement that the disclosure be up to the minute.
My suggestion is that you buy current disclosures from a vendor -there is no way you could cost justify the time and research involved in writing them yourself. Distribute the revised disclosures at account inception, but avoid "the big lie;" there is no requirement that you distribute revised disclosures to existing IRA account holders due to the changes made by the Pension Protection Act.