You must, must, must... try and get north of the Great Glen. The scenery is EPIC, and there's a train (you can hire at Inverness). There should be the first frosts which will calm the midges down (but take insect repellent anyway). Fort William, Skye, Ullapool - they're quite a long way but so, so beautiful. https://www.flickr.com/photos/mlloyd4075/24571777571

http://www.invernesstours.com/images/overthebridgetoskye.jpg

Most of all though, have a good time!