Hi Martin, You've got plenty to go at in that area, one which feels like home to me despite never having lived there!
Around Glencoe take the Glen Etive road, it is a meandering single track road which finally, after many miles, ends up at Loch Etive. All the way along there are fabulous views.
On Skye take the road to Elgol, again another wild bit of road but with famous views towards the Cuillins you'll be spoilt for choice for compositions.
Depending on whether you're taking the ferry from Mallaig or driving across the bridge to Skye you've got potential on both routes, the road to Mallaig has plenty of dramatic vistas, the road to the bridge passes Eilean Donan Castle which is famous.
In terms of kit, your usual landscape kit, and some way of weatherproofing it if it isn't already, particularly on Skye the conditions can change from minute to minute, often with heavy rain. The foregrounds around this area can be very dark, so either ND grads or exposure blending will often be required.
Have a great trip, it is a wonderful part of the world, and feel free to email me (mark at mydomain) if you need any more help.