Yeah you want an av receiver with HDMI inputs not optical, as then your video and audio is hd and can transmit via the same cable. You'll also want a 3D hd receiver if you want to play with full 3D sound as well as visuals.
I'm in the same boat, got Apple TV, sky hd, Xbox and 3d blu ray so looking for a box that will take at least 5hdmi inputs and then everything outputs to the tv/surround sound. Looking at the onkyo but haven't had time to properly test, your best bet is visit a proper hifi shop to see/hear them in action. Though your sound will only be as good as your speakers (to a certain extent).