It's wonderful to see that you and your husband are planning a holiday to Ireland next April and of course I would be more than happy to help you find all the information you will need to plan the most wonderful holiday.
Ireland has always been a very welcoming country and there has been plenty of effort made to make Ireland accessible to visitors who may have reduced mobility, or rely on the assistance of a care taker. You can find our article about travelling with reduced mobility in Ireland via the following link: http://www.ireland.com/en-us/accommodation/articles/accessibility/
I have put together a list of specialized car rental companies for you here:
•Adapted Vehicle Hire
Of course, there are also plenty of helpful companies who rent out scooters and electric wheelchairs, that I have listed for you here:
Finally, I have also put together a couple of other websites that you might find helpful for your holiday:
(here you may choose “Wheelchair access” in the second step of your search.)
Hopefully this information is helpful to you.