I was looking for some specific things in a fish when I did my searches, as the fish was to be a tankmate to seahorses. Thus, my main concern was that the fish in question be PEACEFUL. Beyond that, I wanted a fish that was on the small side (3" or smaller), colorful, diurnal, and would act as a dither fish (i.e. be out and about in the upper level of the tank, which is why I didn't get yellowhead jawfish.) The fish also had to be somewhat hardy, as I figured most of my time would be spent on my seahorses.
Thus, I gave up any notion of anthias. Most can't be considered "peaceful," and those that can don't have a great success rating in captivity. My first choice was one of the Assessor spp., although I knew that they wouldn't act as a dither fish. But Assessors have been difficult to acquire, esp. in numbers, here in the States. I considered the chalk bass for a long time, and I plan to get some as soon as I have a seahorse-free tank in which to put them (I decided that they may be too much for the seahorses.)
So I moved on to examine the cardinals and chromis. If I had the opportunity to purchase more Vanderbilt chromis, I would do so in a heartbeat. Especially after my research on cardinalfish. While there are some beautiful cardinalfish species, many of them didn't suit my desires in some way. Some are diural and colorful, but grow large and should be kept singularly, like these gold species w/ blue lines: Apogon aureus, 5.5" and A. chrysotaenia to 4.5" Others are red in color and local, but are solitary and nocturnal: A. maculatus and A. phenax. I have read that the threadfin, A. leptacanthus, is delicate. In reviewing the family, I only found two species that I thought would be suitable: the 3" gold A. sealei, and the slightly smaller red/copper striped cardinalfish, A. margaritophorus. Both are peaceful, diurnal, and should be kept in groups. I have yet to see A. sealei advertised anywhere, but A. margaritophorus is seen on occassion.
Only two A. margaritophorus were available for purchase when I acquired mine locally, and after looking for them for some time, I bought them without hesitation. I have been hesitant to add any additional members to their group. These two fish get along resonably well, although the one sometimes chases the other. If they were actually in a group i assume there would be less chasing. They are always out in the upper part of the aquarium and are completely non-aggressive.