Ha, that'd sure be a time-consuming task! Unless you were playing on emulators with super-speed access, it'd get pretty tedious i'd imagine, especially if you're talking about all the Pokémon, including their un-evolved forms and not just their final forms.
I've only done two challenges here on emulators and those were Ruby and Leaf Green for my Ground Ultimate, and that was while I still had my Dell computer. On a MacBook I can't really find any good emulators, so I had to use my physical versions of Ruby and Fire Red for my Red Ultimate.