Hooking up my PS3 Via Optical Cable on my 5.1 sourround sound system and need some advice on settings...?

[Redz]

So I have a 5.1 Surround Sound system all routed to a Pioneer VSX-816 reciever. Unfortunately, the reciever doesnt have an HDMI input so I'm going to hook up my PS3 through the next best thing: an Optical Cable.
I was searching through the settings in the PS3 and under DVD Audio Settings>Optical Cable, it gives me the choice between LCPM or Bitstream. I have no idea what either of these are.
Which would be better to choose?
Also, does anyone know what setting on the actual amp is best because I just find myself switching between them (settings like "Advanced Movie", "Advanced Game", "TV Surround", "Virtual Surround") I cant choose the right one lol.

Thanks.