I just happen to be looking for a modular power supply with 100% black cables too. Seasonic and EVGA both have psu's with 100% black cables. Several Seasonic psu's have flat ribbon cables. Several EVGA models have fully sleeved cables. Both companies have a reputation for high quality power supplies.
I maintain a psu recommendation list that is listed in a sticky at the very top of this forum section. Here is the link:
Once you zero in on a couple of models you can then see if they made the psu recommendation list and follow the links to the technical reviews. The reviews will give you a pretty good idea of the performance and quality of the psu's.
You can check to see if any model you might be interested is a bad choice. I can tell you right now that there are no Seasonic or EVGA psu's in the psu lemon list.