Could use some help with Car Rental in Ireland

I am in the process of putting together the last parts of my hunting trip with Devon Deer in England. My final bit of planning is to find a rental car in Ireland and England. England is not a problem as my Visa will cover my insurance coverage needs there. This is not the case in Ireland. After reading several horror stories on the web about rental companies putting the screws to Americans who rent a car in Ireland, I thought I would see what some of you world travelers who have rented a car in Ireland might have to say. Any tips or suggestions regarding how to best navigate around the potholes of the Irish car rental agreement? Dave N has given me some good advise about taking pictures of every scratch and dent that the car may have so you don't get stuck paying for a ding you didn't create. It looks like I will have to pay for at least some insurance through the rental car company, but how much? I have read that the price is steep, and even their full coverage often does not cover the windshield, tires/wheels, or undercarriage. Is there one company which you feel is better than the others. I was thinking that it would be best to go with an American owned company as this would allow me to deal with them here in the states if there is an issue after the fact. Thanks in advance for all your help.