Hello Cyril,
A 4-month vacation here in Ireland sounds like a wonderful idea and you will indeed need a haircut in that time!
While in Dublin, there are several
Tourism Offices who may be able to find you a barber who would be able to help with a Viking Haircut.
Although, not in Dublin, the
Headhunters Barbershop & Railway Museum in Enniskillen sounds like a fun place to visit if you plan to travel around the island of Ireland during your time with us!
I'm sure our Industry partners and fellow members will have some advice also.
Martin