We climbed Sgurr Gaorsaic as a separate one day trip from Morvich, though we used the path up Bealach na Sgairne. There are many good spots for wild camping around Loch a'Bhealaich and further on along the river. You could easily combine the Corbett with Sgurr nan Ceathreamhnan via the west top, but that route leaves An Socach as an awkwardly placed sidekick.
I must recommend the approach from Glen Affric and overnighting neat Alltbeithe, we did just that last month and enjoyed every minute