Help with locating headstones please? Donald Fraser, Mowat William, Catherine

[Birdbrain 1948]

I am visiting Caithness shortly and I would love to find any of the graves relating to my ancestors.
Donald Fraser died Feb 24th 1862 in Freswick, Canisbay. In 1861 he appears on the census with his second wife Christina as a grocer residing in Ruthers of Howe. Can anyone direct me to the likely spot where he is buried please?
Also Catherine Fraser (m.s. Mowat) his first wife and my 3 x gt grandmother died on Dec 5th 1855 aged 29 and "buried at Canisbay Churchyard". How would I go about finding the stone?
Also William Mowat (her grandfather) died Aug 15th 1877 in Thurso aged 83 (Thurso must have several churchyards I imagine?)
And his parents William Mowat and Rose McKean died around 1844. I have found an inscription on 'Highland Memorial Inscriptions' which states burial at Canisbay no 433. Any help with what this means please?
I've had some tremendous help from this site in the past. Fingers crossed! 

[MonicaL]

You should contact the North Highland Archives in Wick, see www.caithness.org/atoz/cemeteries/index.htm and make enquiries with them I would suggest.

You will need specific lair no's and plans/maps of the cemeteries in order to be able to identify the specific grave locations. This is important as some of the burial sites you are searching for may not have a gravestone remaining to be able to identify the exact location in any other way.

Monica 

[Birdbrain 1948]

Once again thank you Monica for a swift reply. (You put me in touch with Robert, regarding a previous complicated search).
It seems a bit complicated to try to find headstones in an area I don't know, but you never know!
Thanks again for the suggestion.