There is a german manufacturer as well. I will try and post a link. I found them in Model Military International -a mag for plastic kit modellers which is excellent.
I think the german ones are prepainted from memory, although I have not tried them.
Ordering from the Japenese company is how you say - send them an email with what you want and they send you a paypal invoice.
I have been a bit absent of late, but am doing a US dukw and 105 gun at present with a crew. I will post some shots once finished.
Our Kublewagen is in production and I have some shots of it ready to post soon.