The WWC ones are Luzonichthys waitei. Seem to be different types.Go to your shop on a quiet moment and ask them where they get what from.
What sources they have good experiences with. Tell them what you are looking for and if they are willing to help you to get those fish.
I always discuss with the shop how they suggest to get a fish I ask for. Over time I have developed some preferences of myself as well. Certain more sensitive fish I rather get from a specific wholesaler or have them transshipped from a certain area and quarantined at the fish store.
The fish that I mention as tank bred, you can just look up at Biota of ORA. Order from them or through your LFS.
All fish I mentioned are hardy fish in my experience and reasonably regularly offered in the trade (a few times a year). But in small numbers so you (or your LFS) need to be on top of it. Here in Europe (The Netherlands) I regularly check the stock of wholesalers myself. De Jong Marine Life and Tropical Marine Centre (TMC) have made their stock list publicly accessible.
I know what day of the week my LFS gets orders in from the wholesalers, so if there is something I want that I had not ordered already I let them know and they bring it in for me. Depending on the fish I let the shop do quarantine or I pick-up the fish in the bag of the wholesaler.
When I feel it is important that a wholesaler doesn't just pick any fish, I know some retailers that regularly go there and hand pick. Then I ask one of them to go and see if one of the fish meets my expectations. In the case of TMC (located in Lisbon, Portugal), they send videos of fish to shop owners on request. Then I can pick a fish from the video.
I have had Luzonichthys whitleyi. They were very hardy and easy to care for.
They are very active fish and really need a place to dart away when they feel threatened.
Even the hardiest of fish can come in bad.
So based on your experience alone I would not deem an group of fish as not hardy.
