3 days is nothing like enough to explore the area - still if it's all you've got then you're not going to run out of hills. As well as Suilven there are lots of upstanding Torridonian sandstone hills of a similar ilk but all very much individuals. Ones I've enjoyed are Quinag (3 Corbett's on one hill so quite a lot of up and down), Stac Pollaidh (short) and Ben More Coigach but there are plenty of others. If the weather is poor then there are plenty of coastal options - just look at your map. Oh, and the walk up to see the caves above Inchnadamph is interesting. A bit like being back in the Dales.