Hi Caroline,
the "Ring of Kerry" is a magical and wild place. If you go along the "Wild Atlantic Way" you will find many other gems like the Ring of Kerry.
For the county of Donegal, I have to say this is my favorite place in Ireland. To tell you, I got married there last year.
You could have a look at Malin Beg for accommodation. It's not far from Donegal town, the cliffs of Slieve League and the beach there is magnificent. From Malin Beg, a road not to be missed is the Glengesh Pass.
Do not forget to share your photos on your return :)
Elodie