Don't think there is such a site but as for numbers it varies on many factors. Bioload, size and temperament of fish, what you are looking for. I am setting up a 75 myself and slowly stocking it. I will have 4 Pearls gouramis (4 in in size) for the top, 2 schools ( ember tetras, Harlequin Rasboras) for the center, and for the bottom 2 small sets of cories total around 14 and a few oto's around 7 or so. Depending on how you plant some fish may not be seen all the time. I would think of what your main fish will be to keep and build around that. Example don't keep Neons with Angels they will turn into food.