Of course, the Onkyo/Integra will accept ANY output from the player via HDMI. The issue comes down to other matters. If you need the other facilities of the prepro (especially room EQ), then that will do everything for you. If you are more concerned with stereo signal purity and don't need MCH, the JC-2 via XLRs is the choice.
In an ideal world, get the prepro AND the JC-2 or P7!
In an ideal world, get the prepro AND the JC-2 or P7!