I know he has his critics but Luiz is good on the ball and has the speed to cope in our high line. I also think most of his defensive errors are from being in a team that defends deep, he's not a Terry like player (Terry suffered in a high line, while Luiz would do well in that system). He's the defender with the most Barça DNA out there in terms of playing style.
He's probably the best available out of the big names that are left. Although nothing suggests that Chelsea would sell him. I'm just worried that he's too similar to Pique and we need a defender that can cover, I'm not sure that's Luiz game usually the other centre back covers for him.