Do you know any good gardens or places to buy plants in the Republic?

At the end of May, I shall be touring in a motorcaravan with my
father, arriving at Rosslare and most probably moving along the south
coast then up the West coast. We have been to Ireland many times
before and I always like to see whether I can get a good plant or two
that is not so common here.

Unfortunately, my father is one of those drivers who demands lots of
prior warning that a stop is going to be expected, so just seeing a
place as we go along doesn't work! One added problem for us is the
size of the vehicle - so many places in Ireland have height barriers
we cannot pass. The other problem for garden visiting is that my
father has to use either a wheelchair or an electric scooter (which we
have with us) so steep slopes or deep gravel on paths are no-no's.

I would be grateful for any suggestions.

Regards, VivienB