Hi, Pam,
Thanks for the backup on the B869!. One of my favorite memories from that area is having a picnic at the benches at Drumbeg, overlooking Eddrachillis Bay, on a beautiful sunny June afternoon. What I really like about that area, other than the coast, are the mountain peaks that stand alone - Canisp, Quinag, and especially Suilven.
@Standing Stone - to echo what Pam wrote, you can certainly accomplish all of this in three days. You'll be tempted, however, to spend a bit of time in many places.
The Cape Wrath visit is okay. There's not much to see once you get there, other than the lighthouse and the cliffs. The minibus ride is something else! The road out there is a mess of potholes. However, if you think that you'd like to visit, even if just to say that you'd been there, check out Bill Bryson's description in his latest book about British travel, "The Road to Little Dribbling." Or you can look up that section of the book on the internet.
I remembered two stops that you should make while you're in that vicinity. Both in the same area. Just north of Scourie, there is an unclassified single track road which leads to the hamlets of Foindle, Fanagmore, and Tarbet. Take the road clockwise to Tarbet, and from there, you can take a small boat out to Handa Island, which is a bird sanctuary. There is a not too strenuous walk around the island where you have a pretty good chance of seeing puffins out on the sea stack, and being dive bombed by great skuas and Arctic terns.
The second stop that you should make is also in Tarbet. The Shorehouse Restaurant is one of Scotland's hidden treasures. If you don't believe me, check out the reviews! Not only is the food wonderful, but they play traditional Scottish folk music on their sound system/boombox. I've only been there, and Handa Island, once, but now that I'm remembering it, I so want to go back.
You're fortunate in that most of the A roads in Scotland are now two lanes. When I first started visiting Scotland many years ago, just about every road north and west of the Caledonian Canal was a single lane road with passing places. The A830 was an absolute nightmare. I remember just missing the last ferry to Skye on a Saturday evening out of Mallaig, and having to backtrack to Fort William because there was no ferry service on Sunday. If there hadn't been a self service petrol pump at Arisaig, which took 50p pieces, I'd have run out of fuel before I got back to Fort William! Ah, memories!
Have a wonderful time, and enjoy every bit of that scenery!
Mike (auchterless)