In FM09 I signed Hamsik and they became a very good midfielder duo, but the slovakian resulted to be a better player than Fabregas, because I used to switch their roles.
If you're going to use only 2 midfielders you'll need a more defensive one, so I could suggest you Angelo Palombo, Miguel Veloso, Steven Defour, Sandro... The most expensive one should be De Rossi, I'll try him first.
Good luck!