Here are some links to resources that may be of interest to you:

Picture
Publishers:
The Columba Press                http://www.columba.ie/  
Veritas                                  http://www.veritas.ie/  
Decani Music                         http://www.decanimusic.co.uk/  
OCP Publications                   http://www.ocp.org/
GIA Publications                     http://www.giamusic.com/
World Library Publications       http://www.wlpmusic.com/

Picture
Composers:
Ian Callanan                            http://www.iancallanan.com/
Patrick Killeen                        http://www.patrickkilleen.com/
Liam Lawton                           http://www.liamlawton.com/
Colin Mawby                           http://www.music-for-church-choirs.com/
Ronan McDonagh                    http://www.fuaimlaoi.com/