I think im going to knock the idea on the head, i'd love to have a regal tang as i think they are a brilliant looking fish but as they can be quite aggressive and suseptable to white spot i'll give them a miss, hopefully i'll get one when i get a massive tank one day.
I can agree that Tangs of all varieties are susceptible to whitespot and we tried 3 or 4 differnt ones in the early stages and lost them all to ich.We also bought quite big specimens. I must admit in a large tank we haven't found tangs aggressive at all although they may be towards their own kind, especially those of a similar shape. You can keep for example a regal tang and a yellow tang as they are differernt in shape. The only way we had success with Tangs was to purposely buy a very small one - and I do mean a baby one. It was basicaly growing in captivity and was more tolerant to the changes (wild to captive..). It has never had whitespot and has grown to about 3-4 inches now. I have no problems what so ever with aggressiveness.
Sorry but that is just plain wrong, really bad advice, there are NO regals bred for nano tanks. What they must have a just really young one's, I see them all the time @ TMC. They WILL grow very, very large, that is unless they're put in a nano in which case they will die, sorry but they will.