Here are some useful tips:
As the venue is so important, try to carry out a venue visit to ensure you make the right decision. Wedding venues abroad do get booked up 12 months in advance – also, it is much more acceptable (and cheaper!) to get married during the week.
A good wedding planner can advise you on the availability of other wedding services you require in the area & can translate.
It is important that you check out the legalities you need to meet in order to get married in the location you choose. Some countries require you to be a resident there for a certain period of time. Check out British or Irish Embassy website.
Run the idea past your family and friends first to see if they would be happy to travel to your wedding. Then give them as much notice as possible so they can plan ahead.
Do lots of research for your guests to help them to have a more relaxed and enjoyable time. You could look into accommodation options, car hire, activities that are available etc.