We got the train to Corrour, done Stob Ban and then stayed at Meanach Bothy for the night. Instead you could camp below Stob Ban at the small lochan at NN 264 729 then push on and do the Grey Corries or if you're feeling fit and have time to push on, then the Munro top, Sgurr Choinnich Beag is nice and grassy for a summit camp, then drop into Glen Nevis in the morning and back out to Fort William.