Any question answered...

Have been recommended to get MTB instead of road shoes despite the fact that I don't plan on mountain biking.. but more for Tesco shopping and not sliding around the place!

Can anyone recommend a good mid-range shoe that will also be comfortable for a long cycle (6 days - Malin to Mizen Head in Ireland).

If you want to do both of these things, you might be happier with these kind of pedals instead:

http://www.chainreactioncycles.com/shimano-xt-spd-trekking-t780-mtb-pedals/rp-prod67250

You'll then be able to ride with either MTB shoes for your touring cycling, or normal shoes for when you're doing things that involve walking around town (shopping in cleats gets really old, really quickly).