Hiring a person to recite the Qur'an for the deceased in order to carry out his will is a Bid`ah (innovation in religion), so executing it is not permissible according to the statement of the Prophet (peace be upon him):
Whoever performs an action for which there is no sanction from our behalf, is to be rejected.
And his statement (peace be upon him):
Whoever introduces something into this affair of ours that is not of it is to be rejected.
The money which the dead person left for hiring a Qur'an reciter should be spent on charitable causes. It may be spent on poor relatives and fulfilling their needs. It can be spent on Qur'an students and those seeking knowledge who need, and deserve financial assistance. It also can be spent on other charitable projects. (Part No. 16; Page No. 336) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.