Sorry, I did not realise this was a double post. This is the advice I just posted:
You will not need car and driver while you are in Inistioge. You can travel directly to Thomastown by train. If you want to see Kilkenny first you can get off there, leave your bags at the station and get a later train to Thomastown. Check the times at irishrail.ie. From Thomastown, you can get a taxi out to Inistioge - cost approximately 12 euros. I can message you with some taxi numbers.
You can then get a taxi back to Thomastown to pick up a bus to Waterford, from where you can get a connection to Ardmore (change again at Youghal). buseireann.ie. This would take nearly four hours and if you want to spend the day in Inistioge, you would have to leave Inistioge at 3.30 at the latest.
When you are in Ardmore you would probably be as well off to rely on taxis most of the time and perhaps come to a good arrangement with a local taxi driver. There is also a bus to Cork which calls at Youghal and Midleton, which are interesting places.