Moving back to Ireland from Boston 2019

I am originally from Co Louth and my hubby is from Dublin. Currently living in West Boston area, we intend to move back to Ireland in 2019 after kids finish up school in the June. In September 2019, One child will be starting 1st year and other will do transition year into leaving cert years. We have been out of Ireland for 5 years (well will be by 2019). Looking for some feed back on education and secondary schools. Do you think it will be a struggle for the kids to get 'into' the Irish way of education? More concerned for my eldest who will do transition year to ease his way back in. American education is very different and my son, having not done Junior cert in Ireland, will be coming from finishing 9th grade in US. We will not know our exact location (from hubby's job) until nearer the time. We decided if they don't tell us where by Xmas 2018 we will decide a location and see how things progress from there. I have been told to register the boys in schools now (November 2017) So I plan to register them in a school near Cork, a school near Dublin and a school near Dundalk (Co Louth). As these will be the areas of interest for hubby's job and distance from family etc. I would appreciate any help or suggestions from anyone. My kids are now typical US kids and my concern is for their transition back to the Irish way of life :) TIA