It's a tricky one. I agree we've been blessed over last few years with some quality centre backs and would like to see a top quality one come in to partner VVD.
However, we've got a very promising defender in stephens who needs regular games at the top level in order to continue his progression. Who knows, perhaps he could be even better than Fonte? I think a season next to VVD would bring him on leaps and bounds.
At the end of the day, it's the clubs MO to develop youngsters - why wouldn't they continue this with Stephens who has shown he is capable of playing at this level?
Plus, I think you can contribute a fair bit of our defensive problems to the balance in midfield. I love Romeu, but he can't do the job of Morgan and Vic on his own.