I do not know about the former, but some of the plants offered by the latter on eBay are clearly mislabeled. I had contacted the vendor, so I am pretty much sure he knows.
I've ordered from Seattle Orchids quite a few times, never had a problem and plants are good size (for miniatures) and healthy. They ship quickly and answer any and all questions. I will continue to order from them, wish I could visit their greenhouse.
I've not purchased from Big Leaf, I have purchased from Peter on his eBay listings DO. His plants are always nice sized and healthy. He needs to sell more miniatures.