Paphs don't have bulbs, and this is one reason you don't let them dry out completely. Actually, Paphs are a slightly more distgan relative of the rest of orchids anand there has been talk in the past of removing them from the family of orchids. Of course we would all get very upset if they did that. So there are some differences of note, like the fact that they have tough roots and can be repotted any time and like to be repotted often, once or twice a year.
Piping Rock is a Paph and Phrag nursery. I bought a few plants from them at shows. Click on Paphiopedilum at the top of the page.
http://www.pipingrockorchids.com/Bindex.htm
You might also like to check out Orchids of Wickford. I bought 2 seedling P. vietnamense from him, and they are doing well.
http://www.wickfordorchids.com/
Heres one I just noticed. Haven't bought from them tho.
http://www.woodstreamorchids.com/