If you're stopping near Falkirk for the Kelpies and the Falkirk Wheel, I can thoroughly recommend staying at the Arden Country House 5-star B&B near Linlithgow. An immaculate house where you'll have the best breakfasts you have ever seen.
https://www.ardenhouse-scotland.co.uk I know you have already sorted your accommodation, but just in case....
I agree 100% with recommendations for the Applecross peninsular, the turntable ferry across to Skye and, if you have time on your way through the borders, the Jim Clark Museum in Duns is well worth a detour, only small but perfectly formed!
