This is exactly the reason why I'm not a fan of Sturridge out wide on the right. We need to take into account three factors: One, how Ashley Cole influences your formation. Two, the 'Bosingwa Factor' you mentioned. And three, Juan Mata's versatility.
Firstly, I think we can take it as a given that Ashley Cole's a far superior full-back, both offensively and defensively, to Bosingwa, and therefore needs less protection from his winger. That's not to say he doesn't need ANY protection, merely that the left side of your team is more stable than your right. Cole also puts in a massive shift offensively, using the space an inside forward on the left gives him (such as Juan Mata) to get high up the pitch. Against Villa, his average position was level with Sturridge, which says a lot. Therefore, we can more or less take it for granted that Chelsea need a LWer that will cut inside in order to get the best from him.
So, with Bosingwa arguably the weak point of your entire team, it would seem obvious that you need someone to help him out. Sturridge, whilst good, doesn't do that. I therefore think that moving Sturridge to the left, as he's reasonably two-footed, and moving Mata into the centre would free up a space for the hard working winger to play in the area he's needed most, protecting Bosingwa. Seems to me like the best use of your resources in this situation.
I still hold that Chelsea should play a 4-2-3-1 - as, indeed, I have for quite some time now - and Juan Mata should be moved into the centre. He's intelligent enough in his movement to escape tight marking, and important enough creatively to warrant a place where he can influence the game the most. As such, another (starting) attacking central midfielder just seems like a waste considering that it doesn't solve any of the problems you have, rather just attempts to keep slotting the square peg of Sturridge into the round hole of a hard-working winger. Not to mention the fact that, unlike now, if Mata drifted in from the left of a 4-2-3-1 he would end up playing in the same space as the attacking midfielder, and whilst fluidity is to be desired, in these situations the two playmakers often end up getting in each other's way and occupying each other's space rather than switching seamlessly.
EDIT: I reckon Sturridge could make it as a striker at this level. He's **** quick, has a good touch and control and has time to sharpen up his finishing. Still, guess that's a discussion for another time.
A midfield duo of Romeu and Ramires would be tasty. Balanced, and complementary. Exactly why I wouldn't field Essien alongside someone like Ramires, they're too similar.