Pape Diakhate(D. Kiev), at the start I got him for 1.3m, brilliant defender, and you can make huge profit.
Onyekachi Apam(Nice), for around 3.8m, good young player.
Isaac Okoronkwo(FC Moscow) for less than 500k, good budget signing.
Sol Campbell(Free) always worth a look, also helpful for bringing on the youth.
These should all sign for Birmingham, and shouldnt want much in wages either.
Hope this helps!