I don't know any specific gun shops since I haven't been there myself. But my wife just visited Ireland and found a book for me that I have enjoyed reading. It is titled "Rough Shooting in Ireland" by Douglas Butler. Published in '06. It is available from
www.merlinunwin.co.ukMy wife told me she found this book in a sporting goods store in either Enis or Galway. She also said there were gun stores/sporting goods stores just about everywhere they went.
I might have to travel over to Ireland with her next time. One of the hosts of a bed & breakfast where they stayed for several days was kind enough to say I could go hunting or fishing with him if I came over with her.
If you enjoy Irish whiskey, I recommend that you try some Green Spot. It is not imported in to the US. Available at the Jameson distillery. My wife was kind enough to bring a bottle back for me. The only problem is that she really likes it too....