A week based out of Kentallen (near Glencoe) - day trips, maybe Isle of Skye?

You might consider touring Mull, which is much closer than Skye. Kentallen is very close to the ferry at Corran, which lands you on (if I recall the name) the Morvern peninsula. It is a beautiful drive from there to the ferry at Lochaline, which takes you to Mull. (There is also a very large car ferry at Oban, but we like to take the small ones.)

Mull itself is beautiful, and Tobermory is worth seeing. Also you can take another short ferry from Mull to Iona, which is sensational--natural beauty combined with gorgeous old ruins.

There are many websites devoted to hiking on Mull; also we like this book a lot:
https://smile.amazon.com/Mull-Iona-Favourite-Pocket-Mountains/dp/190702509X/ref=sr_1_2?ie=UTF8&qid=1492541715&sr=8-2&keywords=hiking+mull

Have a great trip :-)

When you drive to Inverness, along the northern shore of Loch Ness you can stop at Urquhart Castle (walking tours a few times/day included in the entry fee, and costumed interpreters as well as informative signboards) and the Loch Ness Centre & Exhibition (a fairly scientific review of the history & mystery of the "monster" sightings). I believe there's also a boat trip on Loch Ness that docks on the grounds of Urquhart Castle.

If you're looking for a bargain meal in the neighborhood of Ben Nevis, the Morrison's supermarket near the train station in Fort William has a self-serve cafeteria with very good food at great prices. Fort William is well supplied with stores selling hiking gear in case you need anything, and the TI office is helpful. There's a building with coin-entry public toilets facing the water near the West End Car Park and the ferry landing. Also, outside of Fort William, Old Inverlochy Castle and Neptune's Staircase (series of locks on Caledonian Canal at Banavie) are both worth a visit.

Just outside Spean Bridge on the A82 is the Commando's Memorial. It's a wonderful little stop with great view and an amazing story of dedication and courage.