Hi Theodore,
I have ordered multiple times from Exotic Plant Company and always received very good quality plants. They do have a nice broad range of Paphiopedilums. I purchased one of the sanderianum seedling last year and it is good quality, probably a few years from flowering for me, but growing very well. They are indeed located in The Netherlands, Europe.
I personally belief that shipping a single plant in/out of the European Union is not going to be very realistic. There will be a lot of expensive administration to be done by both seller and buyer. I have never done it myself, but I belief it involves buyer obtaining an Import CITES permit, seller obtaining an Export CITES permit, seller obtaining a Phytosanitary certificate, you have to consider more than average shipping cost, potential brokerage charges, customs import taxes. Maybe my list is not even complete... All this could add hundreds of euros to your purchase. Even if all the administration goes well, you still have the risk that the shipping of a single plant across the globe goes 'less than perfect' and you might risk damages or delays. This is why I have never considered it myself. Maybe others have different experiences.
Hope this helps