Thanks.
Here is the website for Russian Vityaz. The English version of the website has been under construction forever so you'll have to fumble your way around the Russian version. Click the book to get into the catalogue section.
http://ruvit.ru/
Here is a quicklink to the Samurai section.
http://ruvit.ru/ru/pages/315/?>
I've come across a couple dealers who carry their figures but I've only dealt with Boris Kolomytsev (aka Kolobob). Here is a link to his website. Don't let the poor quality of the website put you off. There is a lot of good stuff there. He also sells via eBay (just type in kolobob to find his store)
http://www.soldiers-russia.com/
Now an important thing to keep in mind with these figures is that there are different degrees of detail and difficulty in the painting. Boris uses a scale that goes up to 10/10. If you find a figure you like you can request to have it painted to the level of detail you like (and can afford). It is important to keep in mind that prices on these figures are exponential. So a figure painted to 7/10 may sell for $100 at 8/10 it would be $200 and at 9/10 it would be $400. You can't request a figure to be painted to 10/10. Here is a comparison:
http://www.soldiers-russia.com/kolobob/why_pay_more.htm
A normal Russian Vityaz foot samurai figure painted to 9/10 is $472. A figure with a flag is an additional $68 for a total of $540 which is what that figure cost. The beauty of the custom order option is that if you find a figure you like but you don't want to pay the astronomical price you can simply get it painted to a lower level of detail. BTW I would rate Aeroart figures on average at 7/10.