Through the Looking Glass is a nationally recognised centre in the United States that has pioneered research, training and services for families where a child, parent or grandparent has a disability. They publish a book about adaptive babycare equipment that you may find useful.
There are also a limited number of companies making adaptive parenting equipment in New Zealand.
Medifab design, import, stock and manufacture products which can be seen on their website.
Technical Aid to the Disabled is an Australian company that custom-makes adaptive baby-care equipment.