1. For how many ranchu you should keep, I would like to recommend that you buy as few as possilble for your aquarium. Remember that ranchu grow quickly in our weather. My fish grow to over 20 cms in my pond. Space is the most important factor in order to promote the right growth.
2. Ranchu in Bangkok is not as expensive as in SG and there are quite a number of place where you can go. I run one of the biggest breeding farm of topview ranchu in Thailand called Absolute Fisheries, and you can come buy to check us out after you look around in the Jatujak market. There are a few retail ranchu dealers in the Jatujak market, but you need to know a bit about how to choose fish, since the prices will be up to how good you are at talking to the seller.
There are quite a few farms for topview in Bangkok but most of them are small breeders that do no have much selection. I know almost all the breeders and would love to help hooking you up. Most of the breeders are our clients since most of the breeders will buy the Japanese seeds from us. One thing is that you will need to know how to get around, since most of the breeders do not live very close to Central Bangkok. If any of you are ever in my neck of the wood, give me an SMS or an e-mail ahead of time, and provide me a bit of info in what you are looking for, I would be happy to introduce you to any breeders that you are interested in. You could also check out some of the breeders at
www.ranchushop.com, most of them would have a banner at the Home page there. Get your self abit aquainted with the people, and I could give you an introduction to any one you desire.
3. As I have posted earlier, the Nichiran standard (translated as Japanese Standard) is set by the Japanese Ranchu Association.