Remember the D3 is an SPDIF DAC not a USB DAC, so it's USB port is only for supplying power, and you have to use the SPDIF connection from your motherboard to drive it.
The D3 is still a good option, but the Sabre will be much easier to wire, because you only have to plug 1 end into a USB port and the other end has a 3.5mm stereo jack. And the ESS DAC is much cleaner than the D3's Cirrus DAC.
I don't have a center channel, so am only using 6 outputs from the MS-8, with 2 Fronts, 2 Sides, and 2 Subs, so I am using 6 outputs. The full blown recommended MS-8 configuration is 2 Fronts, a Center, 2 Sides, 2 Rears, and 1 Sub.