I saw your posting on the Clare mailing list. I'm afraid the answer is still along the same lines, but I'll try to add to it here for clarification.
If you don't know which parish to look in, then you may as well start alphabetically, or take a .22 and start shooting fish in the barrel! If you have exhausted every source in the country to which these two emigrated, then there's really nothing else to do.
The two surnames you're seeking occur together in every single county in Ireland during the period of the Griffith's Val. 1855-1864. What brings you to Clare for your search? In other words, what document(s) have you uncovered that tell you that's the county they were from?