If I were to extend someone it would be Sully, but I'd rather wait until 2016 free-agency for cap reasons.
It depends on what we do this off season though, if we increase guaranteed money for next year, then extending either might not be the good move, even if you economize in contract value (if the intent is to keep them beyond this season).
If we don't take on any significant guaranteed contract, then I'd be looking seriously in finding an extension for Sully.
But even so, this is not a decision I'd have to make now. It's a decision to analyse in 4 or so months from now and it'll highly depend on what we do this Summer.