the problem with chelsea is that you have a lot of old players with high wages and that you don't have any budget at the beginning. I would suggest you to sell some of the high earner like Zhirkov who aren't that good and get some good youngsters. after 1 season you will be able to sign more players.
Here are some good youngster:
Romario (Vitoria)
Labyad (PSV)
Kevin (Zaragoza)
Dennis Appiah (Monaco)
Lucas Digne (Lille)
Darnel Situ (Lens)
Kadlec (Sparta Prague)
Badelj (Dinamo Zagreb)
Vrsaljko ''
Gabriel Torje (Bukarest)