I think you will find the cost of living in Ireland generally less than the UK, although the economic 'boom' has been causing it to go up.

Shannon is not what you would call a 'City,' per se - Limerick, Ireland's second largest city, is the closest 'large city' to Shannon airport. But in the area between Limerick City (Limerick is also a County) & Shannon airport is where the 'Celtic Tiger' is seen in all the new Industrial Parks. Limerick also has an excellent University that draws students from all over. The three cities I would expect DP job opportunities to be the best are Dublin, Ireland's Capital, Limerick and Galway. Galway is on the west coast and at least one major multinational Computer Manufacturer/Software developer has its European headquarters there.

I have heard of some hooliganism and racial attacks in Ireland - Limerick, called 'stab city;' Dublin, some neighborhoods to avoid; and Galway, known as a pretty tough place; and like everywhere, there are drugs. I've not experienced any of those, likely because I am Irish and much of the violence (except drug-related) is directed against obviously non-Irish people. You shouldn't encounter any of that - just get yourself a Donegal tweed jacket & cap and look Irish.

If you want to see what kind of countryside you will find in Ireland, take a trip to Pontevedra - that's where the Celts came from who settled parts of Ireland more than 2,000 years ago.