[heehee62]

I've got a Rotel RSX 1056 sound receiver.  Here's the backpanel drawing.
 
http://www.rotel.com/content/backpanel%20drawings%20archived/rsx1056-bk.pdf
 
I'm thinking about getting either one of these interfaces:
 
Motu Ultralight-mk3 hybrid:
 
http://www.guitarcenter.com/MOTU-UltraLite-mk3-Hybrid-Audio-Interface-105767958-i1500997.gc
 
OR  Presonus Audio Box USB
 
http://www.guitarcenter.com/PreSonus-AudioBox-USB-2X2-USB-Recording-System-104841978-i1388074.gc
 
Am I going to be able to connect either of these two devices to my Rotel RSX 1056?  If so, with what type of cable?  Also, can I get digital surround 5.1 with either of these interfaces when I play a blue ray on my laptop that is connected to the interface via usb (and then to the Rotel sound reciever)?
 
I thought the S/PDIF output available on both the interfaces I'm considering was the same as the coaxial digital on my Rotel but looking at the photos of the connector sockets, I'm not sure if that's the case.  I'm open to gettin a different interface than these but I'm wanting to connect my midi yamaha motif xs8 keyboard, electric guitar, and 2 xlr connector microphones to my laptop as well for recording/creating music and karaoke (using karafun program).  I've got a set of bm58 speakers I use for my midi keyboard right now and 5.1 speakers for my home theatre system for movies and karaoke if that makes any difference.  I want to be able to switch sound output to between the two sets of speakers without having to unplug the wires every time but I think that may be impossible.
 
Thanks.