Interesting discussion.
IMHO, there is another reason why breeders outside of Japan have to struggle harder than their Japanese counterparts. And thats the fact that most people are unwilling to pay for a koi of equal quality the same price when it was bred by a domestic breeder as they would for a koi bred by a Japanese breeder.
This makes it harder for the domestic breeder to compete with his Japanese counterpart, because he will get paid less for the same product. This will lead to him being unable to buy the same grade of oyagoi than his Japanese colleage, and/or he will be forced to sell more koi to earn a living, and therfor can not cull as stringently. Both of these will result in lower quality koi produced, and/or making it nearly impossible to catch up.
IMHO, if we want domestic breeders to produce better quality koi and give them a chance to catch up, we must support them by paying the price!
As to the original question posted, Israeli koi were imported during the nineties into northwestern Europe. They were better quality to price in the lower quality classes because less stringent culling and cheaper transportation costs. Butt after the massive import of KHV in 1998, generally believed to have come from Israel, and the fact that the koi in Israel will be injected with a KHV serum, no respectable koi dealer will sell them. They may still be sold in gardencentres.
As for domestic breeders, there are some here in Holland. Some breed for gardencentres, and their koi are "nice and colorfull". There are some that are more serious, and these are dealers of Japanese koi that started breeding. They are very respectable dealers, but they will all tell you that there is no substitute for Japanese bred koi. Even though one of them has bought this years All Japan Male Mature Champion to breed with.
http://www.aenc-koi.com/koi_worldclass.htm
Regenmeneer