In reply to billyoxford:
You're in luck: the area could have been tailor made for wild backpacking peak bagging missions.
Stevo's Fisherfield suggestion is a brilliant option but just staying with your preferred Assynt type area there's plenty to be getting on with. Save Fisherfield for another trip maybe.
A random thought:
One problem with linking Suilven with its immediate neighbours to the south such as Cul Mor is the water. Loch Veyatie and the Fionn Loch are right in the way. You could aim to swim, or as some have done to good effect carry an inflatable... but it's a hassle I've not personally bothered with. The same is true to a less drastic extent if you're wanting to link Ben More Coigach with the Assynt heartland (though the water is more easily outflanked here).
Instead of all that, what about starting in Lochinver (shop, accommodation) and doing a big 4-day (ish) semicircle: first inland to Suilven, then Canisp (well worthwhile for views alone), then down to Inchnadamph. You could do that all in a single day or stretch it over two with a wild camp/bothy en route. There's a hostel at Inchnadamph. From here you've a couple of options to get onto Ben More Assynt and Conival (do you like scrambling?). Then continue NW along the high ground to Glas Bheinn. Another wild camp maybe. Across the road you've then got Quinag, which would be the icing on the cake for this particular round. After than you've either got to contrive a long low-level wiggle back to Lochinver (bogs and dozens of lochans will complicate matters, but I'm sure it's do-able), or drop to the road nr west end of Loch assynt and then just a short hitchhike back to town...
Alternatively:
Kylesku to Inchnadamph as a (wiggly) linear walk with a hitchhike back to the start. Loch Glendu; Glencoul bothy; Stac of Glencoul; Eas a' Chuall Aluinn waterfall (is this britain's highest? I can't remember); then glas Bheinn to Ben More Assynt and Conival. Quick getaway option to Inchnadamph from here for a hostel night, or alternatively do Breabag too, which is a fascinating hill. Then down to the road via the Bone Caves, and chance your arm for a ride home.