I only have good things to say about Whitney Maille. They have a large selection of Black Glass and Rainbow titanium ring sizes available to choose from as well as kits and findings. The Black Glass titanium rings I ordered were shipped out quickly and their quality is absolutely amazing.
When I had a question about a ring size being suitable for a weave, they went above and beyond and made a test strip of the weave for confirmation before I purchased the rings. It's not every day you come across customer service of that caliber.
If you're in the market for Black Glass titanium, I recommend them without hesitation. I see many more purchases in my future.