75ohm vs 110ohm digital cables

I am seeking some clarification. I have a Esoteric transport and DAC and am looking to upgrade the digital cables to a dual XLR (being the units can accept that). In looking at cables some are 75ohm and some are 110ohm. I cannot find anything in the manuals that states which should be used? Any clarification here would be useful as I am reluctant to purchase anything till I am confident I am getting the right one. Is this something that is user choice? Any impact on sound quality?

Thanks