Digital Cable Help

I am thinking of adding a DAC, probably the Benchmark, to my system. I have a modifeid Sony 9000es CD/SACD player. I have never owned a DAC before and am totally ignorant about digital cables, the differences between them and which one would be best suited for my use. Any suggestions will be most apprecaited.

I also assume if I switch from SACD to CD playback with the Benchmark that I'll have to switch my analogue interconnect cables from the Sony to the Benchmark (unless I purchase another set) interconnects cables.

Thanks