Easy to do yourself, especially if there is only a couple of you.
Figure out how long the trip will be and then come up with a list of courses. Some courses only allow play on certain days and certain times, so having more courses than you can play is good incase of substitutions. You should also try to book as soon as their books open for the following year to avoid disappointment.
The problem with Ireland is there are fantastic courses all around the island. So you need to have a bit of a gameplan.