Well first off if your looking for the one compatible with 3G over USB, you will need the European one. Otherwise, I don't think your router maters in way of compatibility, just your ISP. Do you have DSL, ADSL, Cable(broadband), or 3G? The only think specific I can think about ireland is some their actual infrastructure is wireless, so they have a reallly high latency rate. Also, their starting to crack down on pirating. Other then that, should be in the clear. Cheers!