There's no problem finding alcohol. You can buy it readily in outdoor shops in Glasgow and elsewhere and as you walk you will find in Drumnadrochit, Fort Augustus, Aviemore and many other places besides.

I often mail a bottle of alcohol in my food drops. Once your route is sorted out I can do the same for you if appropriate.

You won't get by on on Jetboil canister but as others have said you will be able to resupply en route.

Always carry a spare or two!

Thanks Andy