I think my wish list has looked the same for the last two years now. I want Manolas and one of Jorginho and Fabinho; ideally the latter who also comes with that physical superiority that we've been lacking throughout. Proper two-way player. It'd be like having Vieira around again.
I'd look for a keeper after that. Samir Handanovic would be ideal to me, I think he's absolutely brilliant, but I'm not sure whether Inter would let him go. He's 33 now though. If a good bid comes in they might be tempted.
Worst case scenario I think we can push on with Cech for another year, though I rather not. He had a pretty good season up until a month ago. A team that leaves him less exposed would probably reduce the number of errors he makes. It's not ideal but I would still prioritise outfield players this summer.