Hi Matt. Welcome on-board
Bimbler on here is also from your neck of the woods and I'm sure he'll be along to offer his support. He's only 5 miles further from Squires than you are
In my opinion you've chosen one of the better route directions. It's always great riding down through Glen Coe and the last stretch back down the A1 never seems as bad as the long drag down the M6 and across the M62 as the anti-clockwise direction does.
One of the keys to success (after some practice of course) is to plan your fuel stops and try and ride until you need to stop and top up. You can then use these stops to eat, drink, and pee. It's all too easy especially in the highlands to keep stopping to take in the scenery, but it's surprising how all these extra stops can eat into your time.
I'd also consider starting early at 05.00. Many riders choose to start at this time to make the most of the light traffic and daylight. You might only end up riding for a couple of hours in darkness and it's something to brag about when you tell all your friends you've ridden around the whole of Scotland in daylight