There's a company i have sub contracted work to before , they are based in Ardee, if you PM me i'll give you the contact details , he can supply both masons and stone or if you prefer he'll put you in touch with various suppliers and you can buy direct from them yourself.
I've used him on a few sites now and I have to say the quality of his work is excellent, he might not be the cheapest around but badly built stone is desperate to look at .
I have no connection whatsoever with him.