I managed to loose my first post I did on this topic. But in my researches I found those cables from Whirlwind as well. EWI also does them. Just go to the home pages for these manufacturers, and find their local distributors.
Any place that sells audio gear for home studios should be able to get what you want.
You should be able to find this pre-made. Hosa makes some of these - but not exactly the best quality. You should also be able to get a local A/V supplier to make something up for you.
I'm in contact with a dealer from whirlwind about a custom one. If it's too expensive though I may just buy two 8 channel ones from different companies so theyre different.