I did three weeks round Ireland (North and South) - absolutely fabulous - the best parts are along that west coast and the further south you are, the friendlier the people are - Truly the most open and welcoming people, I have ever met! The closer you get to Northern Ireland the more reserved people become - I found this quite sad.
Theres a couple of point though
1) Sadly, this site doesnt cover WC in Ireland

(Use 'Park 4 a night app , intuition and common sense - They are that friendly in Ireland it really felt like it just wasn't an issue.
2) There is no such thing as a National Trust and so visiting places very quickly gets expensive.
3) The ferry there and back will cost you - but travelling by ferry is pretty painless compared to airports (not that you's be taking you motorhome to an airport anyway!)
Ive also been round Wales many times - absolutely great too - bit cheaper as no ferry required and things like National Trust / English Heritage / CADW properties a plenty. Best place in my opinion are over to the West. Dont miss the Llyn peninusla or Pembrokeshire!
If you were choosing between the two then its down to time and money. Ireland - I wouldnt bother for less than three weeks and thats rushing it and missing out most of Northern Ireland! Much better two months. Wales - you can have some impact on that West coast with just two weeks free.
The Hebrides are excellent too and the ferries are so cheap as subsidised by the Scottish government. - They are much bleaker than Ireland or Wales though so depends what rocks your boat! That said, the best pie 'shop' in the world is on Harris - its called Croft 36
https://www.tripadvisor.co.uk/ShowU...ris_Outer_Hebrides_The_Hebrides_Scotland.html
Enjoy!
Melissa