In reply to yorkshiresherpa:
Assuming they're reasonably fit, and only a 'beginner' to Winter, Gulvain might be a reasonable choice - it's at the edge of some rugged, wild terrain, but has no difficulties itself.
It's a fairly long approach up Gleann Fionnlighe, but mostly on a good track.
Be aware that the summit is not the first top, with the Trig Point, but the one further NE (which isn't on the same OS Landranger Map!)
http://www.gaelicplacenames.org/maps/map.html?g=NN003876
http://www.ootnaboot.scot/lochaber200312/gulvainbrockan1.JPG
http://www.ootnaboot.scot/lochaber200312/gulvaintops.JPG
http://www.ootnaboot.scot/lochaber200312/gulvainridge.JPG
Or for a slightly bigger, two-Munro day, there's the circuit of Sgurr nan Coireachan and Sgurr Thuilm a little to the West, right on the edge of the Rough Bounds of Knoydart.
If the above days are longer than you'd like, Meall nan Teanga and Sron a'Choire Ghairbh are not as interesting, but make a shorter, quicker day from the North end of Loch Lochy, and are still well worthwhile in Winter; if struggling, it's easy enough to do one and leave the other for another day.