Does depend on your itinerary and intended mileage each day. Campsites at Easter Drumquhassle, several on Loch lomond shore, Beinglas farm at the end of Loch lomond, two in Tyndrum then nothing until Kinlochleven. Hostels and bunkhouses in Drymen, Rowardennan, Inversnaid, Crianlarich, Tyndrum, Bridge of Orchy, Kingshouse hotel. Bothies at Rowchoish and Doune. Of course a lot will depend on any covid restrictions in place at that time as much is closed or restricted at this time.
Just been on the WHW in mid Sept. Did a hotel in Drymen the first night as LNER and Scotrail combined to leave me in Edinburgh at the time I should have been walking so after a Glasgow train and taxi to Milngavie I was well late in starting. Did 4 nights wild camping after that with camps nr Rowchoish bothy, Crianlarich crossroads, Rannoch moor and in the woods above Kinlochleven.
In answer to your question I would rate the Tyndrum sites the best for facilities and access to others in the village.
Enjoy it, I have now done it 3 times, I usually think of my stopovers first and then work out mileages between