I am with you, I would love for someone to give up the secret on the best source for the #35 chain with the K-1 attachment on every outer link.
I did some searching a while back myself and found it pretty difficult to find. As RC Logger recommended I contacted Viking Industries, but they were not interested in talking to me because I was not a corporation. They told me to go through a distributor like Motion Industries or Applied. Last year the local Motion Industries office priced the #35 K1 chain to me at $48 per foot, but minimum they would sell was 10 feet. I was not willing to shell out $500 for chain. When I contacted Viking, I was talking with the distributor in Georgia that covered my region. It may be different with the distributor in Canada.
I also found this on Amazon, but you cannot use #35 sprockets with it because the roller diameter is larger than a #35 chain. They also dont tell you what length you are getting for that price.
http://www.amazon.com/Roller-chain-a...A28EG6DQRVDN3A
Have you looked at some of the german websites? For the prices I was getting on the chain you could buy actual dozer tracks for about the same amount, and the tracks were much more scale looking.