Can you add a SPDIF input to a CD player?

[Leo V]

So here is my idea:

Add a digital SPDIF input to my Sony DVP-NC650V player, similar to the popular NS500V. This provides several benefits:

1) I could play back my MP3s on my computer using 24-bit MAD decoder (and a 24-bit SPDIF stream), and get the best sound from Sony's 192(96?)Khz, 24-bit AKM DAC.

2) I could play CDs which I digitally extracted onto my hard drive (they are losslessly compressed w/ Monkey's Audio). I could play them back through Sony's DAC--without ever using the transport! No jitter, no paranoia... complete peace of mind!

3) No more shuffling CDs around! I could play audio CDs direct from hard disk.

That's my pitch. So is this practical, or is it very expensive/difficult?
Leo