In reply to Michael Hood:
No need to walk on the A82. There is a path (not marked on OS map) on the S side of the road, starting from the E end of the car park at Achnambeithach, then continuing along the old road from Achtriochtan, before finally slanting up to the A82 near the start of the path up to Am Bodach. Even where the path is close to the road it's generally below road level, doesn't feel like you're walking beside the traffic, and is not unpleasant.
Descending from Sgorr nam Fiannaidh via the Pap of Glencoe path doesn't involve any scrambling, unless you nip up the Pap, but again, is not unpleasant. From the bottom of the Pap path, another foot/cycle path ("Glencoe orbital") takes you to the Clachaig in maybe 30 mins. Maybe another 45 mins to the car from the Clachaig, but reasonable chance of hitching from the junction with the A82, if you want. It could be a bit quicker overall to reverse the ridge, and more 'fun', if you enjoyed it E-W, albeit you will likely be going against the flow on a good day at this time of year. But descending W and coming back along the glen is also fine IMO.