We solve the Eliashberg equations for different models of electron-phonon coupling. In particular we study a coupling which is different on different parts of the Fermi surface in order to look for possible conditions for d-wave pairing. This is of some importance since many recent experiments claim d-wave pairing in YBCO. We find that a very localized interaction (i.e. a strong coupling within certain Fermi surface pieces, but weak coupling between different pieces) together with a Coulomb repulsion is favorable for d-wave pairing. The connection between the models and the calculated coupling and Fermi surface of real copper oxide systems is discussed.