We were in Ireland last year!!! Love love love your country! We were in the southern part of the country because our son was there for his study abroad. I was disappointed we didn't have enough time to head north. Maybe next time!
We live about 45 minutes from Lancaster and took a drive around and visited shops last month. Soooo much fun! Bring an extra suitcase! If we lived closer, we would put you up and give you breakfast and send you out for the day!
Can't advise you on lodgings. The Harrisburg airport is close to that area. In fact, a couple of the shops we visited were close to the airport. From the Philadelphia airport, it's about an hour and a half drive to Lancaster, traffic permitting of course.
Have a fabulous trip!