Doria. Monster CB, and very consistent.
Take a look at Balanta before you sign him. Sometimes, his stats are monstrous, other times, he can become a liability, even.
Marquinhos is ultimate quality, very, very consistent, if a tad too overrated. But I doubt if he'll be available for that price.
Umtiti is an excellent option.
Ideally, Doria, Umtiti, Balanta are your best bets, with that much amount of money. They can partner Chris Smalling, cause you ideally should be using Jones at RB (he's more of a beast there than CB, unless you bought Peruzzi.)