I was looking at the code and thinking about a way to preload pokemon egg groups, what do you think about a list file with all pokemon available on PokeMMO, their egg groups and their pokedex number? That way we can use it for filtering matching options to breed between other things. We can also have the user input the pokedex number of the pokemon he wants to breed until Nx31 or whatever stats he wants. We can also go as far as getting the list of pokemon and where they are available and with which % of appearing in the wild, that way it will be possible to recommend a pokemon easier to catch/buy for the user to make the breeding process cheaper.
Also, what are you planning to use to build the GUI? I'm not well versed in GUI building but I use python everyday and I think we can make a great tool here.