You could consider posting the maps in advance to places on your route where you could pick them up for each stage. "Hamish's Mountain Walk" and Alastair Cawthorne's "Hell of a Journey" both describe extended treks in the Highlands and give details of how the logistics were handled, also both good reads if you haven't come across them already.
Unless you're confining your activities to the central belt the chances of being near a pub every day are fairly small I would say!
By the way, the Landranger 1:50,000 are considered by many to be a better bet for pedestrian navigation in the Scottish Highlands than the Explorer 1: 25,000. Due to over-zealous drawing in of rock features many OS 1:25,000 maps are verging on unusable, at least in the mountain areas. Just have a look at the Skye Cuillin and Torridon maps and you'll see what I mean. I tend to use Harvey (also downloadable from Anquet) for those sort of areas.
But then in the Lakes I would never use the Harvey maps and always use the OS 1:25,000
Call me a luddite but I wouldn't be setting off on a long trip with only GPS and no hard copy maps. But then my GPS is an old Etrex Summit. Good for what it does (add weight to my pack and record positions of secret stashes of whisky), but thirsty on batteries.
Ian
www.mountainfreedom.co.uk