Have you considered purcahsing via the UK store using Parcel Motel? That's how I got mine.
It could be ages before the Watch is released in Ireland because we have no Apple Store here. (And likely will never have one for tax reasons, alas.) Because of the lack of Apple Store, I think we'll be one of the last European countries to see a Watch release.
I would suggest you either hop a train up to the Apple Store in Belfast if you prefer to make a cash purchase, or if you're happy to do it via credit card or Paypal, set up a Parcel Motel account and order via the UK website. You'll be waiting indefinitely otherwise. PM me if you have any further questions about the process!