Heronswood nursery in Washington state:

www.heronswood.com

Or, try Barry's Glick's nursery back east. Is it called Sunshine Farms?

also pine knot farms in virginia sells plants that have bloomed. it's best to buy them in flower so you can get what you think is 'black' or 'blue-black', but at least you'll be more certain of getting one in that general category if you use one of these growers even if you order at other times of year.
there are other places too...just double-check with the one you choose to make sure they are selling a plant that has already bloomed as it is impossible to know with certainty what the color will be--regardless of parentage--if you are buying a seedling.

Here is a link that might be useful: pineknot

Thank you so much.