Thanks "Tall333" and "moozmooz", enough there to let me source the right jack. Looks like the e-bay link to the second jack on "moozmooz" would do the trick, although I will try to get a new unused one rather than that on e-bay.
I have found a supplier of car accessories in Enniskillin, Northern Ireland and will contact them tomorrow to see if they can help with jacks for our Mazda3 & MX5ND.
Thanks again :-)