Further South on the West Coast try:
Jackie Kay, Ardrishaig Boatyard (at the enterance to the Crinan Canal) 01546 603280
(Handy for the Firth of Clyde, Bute, Arran etc but not much else, probably cheapest winter storage in the area)
Crinan Boatyard (opposite side of the Crinan Canal) 01546 830232.
Then Northwarsd towards Oban-
Ardfern Yacht Centre: 018520500247
Craobh Haven: 01852 500222
Kilmelford 01852 200248
Dunstaffnage: 01631 566555
I have a mooring in Ardrishaig and Loch Sween (Achnamara), both capable of taking your boat and both checked out for this season. Still a novice I have not yet managed to work out how to use 2 moorings at the same time, so if you want you could use one for a short time.