Hey Al,
Is Ireland the entire emerald isle or split into Eire and Ulster? For this exercise it might be wise to remain divided to get four Senate seat instead of two!
It'll remain partitioned as O'Neill wouldn't want to upset his base.
What would you do with County Cavan, County Donegal and County Monaghan? They are a part of both Eire and Ulster, but not of Northern Ireland.
Note also that Ireland could be split into the four traditional provinces, Connacht, Munster, Ulster and Leinster. England, unfortunately, does not have such convenient divisions. The only ones that come to mind are based on the Church of England's Provinces, Canterbury (Midlands and South of the Midlands) and York (North of the Midlands).