Is there any particular reason why you need to buy lev (or any foreign currency for that matter) in advance of arriving there?
If you are in Dublin, you could try Thomas Cook at the bottom of Grafton street. They buy and sell lots of currencies that the banks don't deal in.
Preload CC and withdraw money over there? See the many existing threads on the pros and cons of different ways of access foreign currency for travel abroad.Its called being organised.