Just be aware that 600 Watts is the minimum recommended by Nvidia for a reference model GTX 770. If you plan to use the MSI Lightning in the way that it was intended, extreme overclocking, then you might run into a limit. The Lightning uses 2 8-pin cables to draw more power for overclocking, as opposed to the reference 6 + 8-pin power cables.
I still think you're going to be okay. Why? You have a high quality PSU, and the fact that the experts at Guru3d only recommend a 550 Watt PSU on a highly overclocked GTX 770, the Inno3D Herculez:http://www.guru3d.com/articles_pages/inno3d_geforce_gtx_770_ichill_herculez_x3_review,5.html