Thanks, @mitch and @kezo Your thoughts much appreciated. Interesting to hear a favourable note re Karndean. Most of the online reviews are less than complimentary. Damage from spilt water is one of the top minus points and, well, I am a very messy cook! Shall take another look at Karndean.
Waterproof carpet? Had no idea such a thing existed. As above, my skill at being messy in the kitchen would probably trash it within a few days.
Am currently searching for a proper, qualified fitter because whatever we choose will have to be laid by someone else. I simply cannot get down on hands-and-knees without: a) lots of pain and b) inability to get up again!