You must try these players:

Joe Gold - Scottish youngster, he is a free agent at the beginning, or he plays for Cartagonova (or something like that) and he's really cheap (45k or something). He is a defensive midfielder - center
Valeri Emilov Bojinov - Bulgarian youngster (striker), plays for Lecce and he will become an incredible striker. I'm in 2013 with Celtic and he scores twice per game.
David Marshall - Scottish youngster, 15-16 years old, he plays for Celtic and you can get him on a free at the end of the first season. Later, he will become Scotland's National Team Keeper.