Need a very neutral interconnect-

Copper Audioquest sounds great with just about anything. Their silver cables are good too but the results can vary. Purist 20th is not that neutral. I would also look at Kimber Select and Tara. You would probably like them as well. If you call The Cable Company, they will send you anything you want so you can try them in your system first, before you buy.

"I hear people talk about "the blacks" but am clueless what that means."

Its a combination of a very clean top end and a wide dynamic range. All the components in a system contribute to it, and having a good recording also helps.