I'll give you support in spirit in that at least you thought of a club that speaks to my taste in animals. That is to say, in real life, while most people like dogs and cats, I vastly prefer the small fuzzy creatures like lagomorphs and rodents.
Other mice to include would be Marill and whatever its preevo is called. If you opened the club up to all "pocket pets" as it were, it would spike up a bit to include all Nidos, Azumarill, Plusle and Minun, Sandshrew and Sandslash, Buneary and Lopunny, Sentret, Furret, Shaymin and Pachirisu. Granted, not all of these are related to rodents or lagomorphs, but you could still find them in a pet store (save for a shrew or squirrel, I suppose).
I support the Nidoran - Nido Family Union. Do you?