with what you say he should buy almost every player, that aint realistic
Stekelenburg = good (vermeer is also a good keeper)
CB, i would say try to get heitinga if he wants, or go for maduro. DL/DR you have van der wiel, he is good for LB you can go for blind but you might want to improve with tiendalli from twente
MC= You got De jong, keep him, get janssen (twente) and you got de zeeuw and he is good enough
FORWARD = Sulejmani is good, keep him, try to go for Dost, as a striker (Hamdoui is good but dost is a good backup), Try to go for mertens on the LW)
hope this helps you