Welcome to the forum!

Vehicle size is a tough question -- as a LOT depends upon luggage size, quantity and the rest of your travel plans.  For example, with six of us (two of them small children) a 7 passenger Ford Galaxy was adequate, but our luggage spent 11 days 'parked' in a Self-Catering rental house and only spent two short days in the car WITH us.  With 5 adults TOURING, I think you might need to look at a 9 Passenger people mover, like a VW Caravelle.  Realize though, that such are generally QUITE pricey -- and rarely available with an Automatic transmission.

See: http://www.dan-dooley.ie/vehicles.php        http://www.volkswagenvans.ie/content/vw_nfz/importers/ie/brand/en/models/caravelle.html

As to a first night destination, Belfast would be within your two-hour window.  So, too, would Carlingford, in County Louth -- which is a personal favorite of mine.  Both offer lots of touring options, but which to choose would depend upon what the rest of your trip plans entail.

Thanks Bob.  We will be touring for two weeks, so maybe getting two smaller cars would make more sense.  I've always wanted to visit Carlingford and have checked out Carlingford House there as a place to stay.  Don