I would have thought the point of such a list shouldn't be limited to the species being bred. I'm likely to have a small number, or even one, of a certain type of fish (pleco for example) as my tanks aren't big enough to house any more at a time but I'd be more than happy being contacted by someone who wanted to try to pair up mine with their same breed fish for the purposes of breeding - almost like stud farming but for fish - I'd expect my fish to be returned after a sucessful breeding group has been established or replaced depending on the deal which could be made between the 2 parties at the time.
It would take the pressure off getting involved in a special order if I knew I wouldn't then have the country looking at me directly to breed the fish I wanted. I'd be more than willing to lend them out / chip in for a breeding group to then get my pick of the litter (so to speak) once the group was established.
Just an idea but I strongly urge whoever creates the 'new list' (please do so, it would be a great service to offer the community) to not just limit it to people actively breeding the fish they have.
I'm happy to help with whatever I can on this front.