It's great to hear that you are planning a trip to Ireland next year. You certainly have an exciting trip planned by the looks of it.
There are many different options for travelling around Ireland - thankfully, the island isn't too big so getting around is very manageable.Renting vehicles
is certainly one option and renting cars directly at airports will be possible. Travelling by bus
in Ireland is another good option, especially if you are planning to get off the beaten track using public transport during your trip. Going by train
is another option, especially for intercity travel. As you mentioned, private coach hire is also an option, particularly with a larger group.
There are differences in the cost of each of the above options, with public transport being generally more affordable, which is an important factor to consider. I hope this information and these links are helpful to you. Feel free to let us know if you have any other queries.