Integrating OPPO 105D in a home theater ?

My Home theater is using Denon X4100 Receiver as Pre-pro with Sunfire Cinema Grand Amplifier (using RCA connectors). Like Denon as it has Room Calibration and am using 4 HDMI inputs for different devices. But Denon doesnt have a Digital Optical Out. 

I also use this to listen to music time to time. I have a OPPO 105D that I would like to use to listen to music since it has a much better DAC. 

Q1 - Can I connect 2 Sources to the Sunfire Amp ? OPPO 105D (using XLR Inputs) for music and Denon (using RCA inputs for all Home theater - Doesn't seem like a good idea so I haven't attempted it yet.

OR Are there better ways to connect OPPO in the setup Such that I can use OPPOs DAC ?

Thanks everyone in advance.