I highly recommend running the new filter on the old tank for a week or two. This will seed it with bacteria so that your fish don't have to go through the cycle. Once you have a tank established it's generally not necessary to go through the cycle again.
As far as hardiness of these fish go, they are generally hardy fish, but because of popular demand the breeding has become unselective, and bad strains are all too common, making them more susceptable to problems.