LDS Parish register transcripts of Kirk-Christ-Lezayre, 1849-1883 are on film no.0106181.
You may also see other entries of interest on the film. Have a look at Brian Lawson's burials index which includes Lezayre to see the many Clarke and Radcliffe burials there. His index is a great help finding entries when looking through the film.
Also baptisms, seeing they were still in Lezayre for the 1861 census (thanks, Brian).
You have John Radcliffe CLARKE ch. 7 Feb. 1864, Lezayre, and the par reg should have further details. You may find other children missed/misspelt on the IGI, as well as that 1854 bapt you mentioned.
Let me know Cath's father's details when you find him.