FYI: Florida hill, Green Earth Publishing Co, Wellspring Gardens, etc. don't have the real deal blue java, scroll down this post and read my comments:
Want feedback on a website I am considering ordering from.
Looking on this forum to get the real deal ID verified plant is your best bet. A good way to verify the ID of what the vendor is selling is to ask them to send you a link to photos of their plant or a thread that they made on this forum. It might be difficult for them to get a photo of the corm for sale, especially if other buyers don't ask and there's a line for that particular plant.
I've purchased many corms from several vendors here and NEVER had any mis-representation with the size or ID of the plants (I've fruited most of them). If it was small, the vendor warned me. All of the reputable vendors here are gardening folks and will take good care of you. They are generally careful to not to make any mis-representations because they can easily lose their reputation here on the forum.
If you have a dispute with a vendor, it's best to discuss and resolve that dispute privately if possible. Give the seller all the chances possible before resorting to public shaming. Other vendors who have what you're looking for might hesitate to help you because they might be wary of having a thread like this showing up against them.
When it comes to ID verified rare bananas in high demand, it's currently a seller's market (well, it'll probably always be that way), which means that they'll treat you professionally and with courtesy, but if you have a unique demand, they may not be willing to meet it, especially if the rest of the buyers don't have the same demands. For example, in California, when you're buying a house in the SF Bay Area, you have no chance of landing one if you place a 17 day, inspection contingency, since all other bids for the house have no contingencies and they'll buy as is.
In any case, good luck finding that blue java, I'm sure someone here has one for you!