My view on Jonas is he doesn't do enough in the final third, not so much because he isn't capable (some would argue), but because he just doesn't get into the final 3rd enough in the first place. He is, in my view, a wing back. Not quite a full back, but not an all out attacking winger.
So I reckon we need to be playing him in his perfect position, Left Wing Back.
Given the fact we have a another player who isn't quite a full back, nor an all out winger in Santon, we could play him at RWB.
When Saylor is back fit and we sign ourselves a decent centre back comfortable on his left side (hopefully) a formation of 3-5-2 wing backs could be out best formation. Throw in the fact we would have 3 defenders back on all occasions actually strengthens our defence rather than weaken it. Especially at home. Also add to it Cheik and Cabaye sitting in centre midfield, HBA given a free role to work his magic all over the pitch, and still have 2 out and out striker in Ba and Cisse....I like it, I like it a lot. (Obviously this is taking into account no movement out the door)
Even as we speak now, slot Willo in at CB and Simmo in for Saylor, it should still work.
The key to this is Santon and Jonas knowing when to get forward and when to get back, but if they play their natural instinct to do both, it shouldn't be a problem. The stats for Jonas in the above link show he is basically the best defensive winger in the league, so why fight it?