In reply to Frankie boy:
Hmm, some random thoughts, in no particular order:
Skye: The Cuillin has load of stuff you could do depending on how many pitches your dog will wait patiently for... There is Carn Liath as well, not my cup of tea but certainly ok to leave a dog at the bottom and no problems on the approach (except it being inexplicably long and arduous).
Orkney: There's a fair amount of stuff on the gullys on Hoy now that is single pitch but it's only Lang Geo main wall where the dog could walk down with you and keep you company at the bottom, the rest of the geos and walls are abseil approach. On Orkney Mainland some of the stuff at Tankerness and Deerness has short, easy scramble descents you get a dog down and large flat areas of rock at the bottom but it's been brought to my attention that I've made the rock quality in these places sound better than it is in the past. Overall I think you would be missing basically all of the best climbing if you were going to Orkney with the idea of a dog-at-belay.
Shetland: Dunno.
Lewis/Harris: Lots of big scarey multipitches where the dog could watch you disappear off into the sea of rock and lots of sea cliffs which wouldn't be suitable... not a lot of what you are looking for from what I remember but I don't know the Outer Hebs intimately.
Mingulay/Pabay: Amazing climbing, you should absolutely go there (after leaving the dog with someone else).
Your comment about reliable weather brought a smile to my face! (it doesn't exist in NW Scotland).