Yes, I have done business with Yoshihiro (Yoshi) Nakamizu, but not in importing a tree--a little on that in a minute. Yoshi is extremely helpful in getting Japanese bonsai "stuff" in general. He will go that extra mile to get unique Japanese pots, books, tools, etc.
That said, if you want to import a Japanese tree--be prepared to START at around $1,000 and plan on going higher than that if you want the good stuff (good trees can be anywhere from $1,000 to over $15,000 depending on what you're looking at...The REALLY good stuff is priced along the lines of single family homes in the US and mostly doesn't leave Japan)
As for importing, it is an art in itself. Unless you have bottomless patience and deep pockets, it's best left alone...US regulations are quite strict about many plants imported from Japan. Restrictions can vary from species to species, but in general, a two YEAR quarrantine is required before you can accept the plant--if I remember correctly. There is also a documentation requirement --phytosanitary certificate--that also must be met. The quarrantine period can be done in Japan, or at one of a couple of US facilities that have been certified by the US govt.
After all is said and done, you're talking some major $$$.
All of this can be avoided if you buy an already imported plant, but they aren't cheap either, since the importer has to recoup costs and he's taken all the risks. There are bulk importers of cheap stock from China and the trees are mostly low-priced "mallsai" quality--which isn't a bad thing.
For what it's worth, there are many sources of excellent bonsai stock here in the US. Of course the material isn't of the same meticulously groomed quality of the top Japanese stock, but some (especially collected yamadori stock) can approach it. It's also about 1/3 of the price...
Try Evergreengardenworks.com, Internationalbonsai.com, Goldenarrowbonsai.com for good US stock and yamadori to start. There are many others if you look around.
Thanks for the info. I knew it was a pretty intense process that required lots of time. Wasn't sure how much people were spending though, but really i just wanted to know more about it. Definitely don't want to bother importing anything, I'll let other guys deal with that.
I am aware of most of the US vendors for material and thought I had found them all! I was surprised that I had never stumbled upon either Internationalbonsai.com or Goldenarrowbonsai.com. Thanks for those links