> Do I need to get a ferry over the sea, to skye which will end up costing more than driving straight to Ullapool?

Dunno about the caravan consideration, but the "Road to the Isles" that leads to Mallaig, for the ferry to Armadale is rather beautiful!

Ah, look! http://www.road-to-the-isles.org.uk/mallaig.html

Mountains, lochs, coast, cliffs, waterfalls, sea, sky, trees... We drove alongside the Harry Potter train for a mile or so when we were there! And you can send kippers by post when you get there! Andandand... Sorry... Well... I did quite enjoy meself!

G x