2) Connect each of your sources to the Marantz by a digital cable.
Since you say your receiver has the best DAC, then, as Kal said, use digital inputs to it where you can. Since your CD player does not provide a digital ouptut you're stuck with an analog connection for it.
I'm a big fan of Blue Jeans cable for all cabling.
Swanny - my cd player only has stereo (red/white) audio output, which is what I am using now. I am going to take a look at blue jeans to buy some upgraded stuff.
With the components I have, I plan on the following:
Digital Audio out from Cablebox and DVD to Receiver
Stereo Audio out from CD to Receiver
All component video from sources to receiver, then component video output from monitor to TV.
A good source for reasonably priced cables is BetterCables. I just ordered their silver coax cable and will try it out later today with my new Bel Canto DAC3 that is supposed to arrive today! I think this cable cost about 40 bucks with free shipping. I hear you should use at least a 1.5 M length to minimize jitter and bad artifacts. I ordered the 2 M length. 1.5 M seems the ideal length. I bet your receiver does not offer the best DAC and probably not the best jitter reduction.