I'm not getting any just planning for later as still need to redo tank, but i know that they have to be in groups so i was thinking 8 or 10?
Is this too many?
No it's not too many. As stated above, you can have quite a few (though I would personally keep them around 20). Only because I don't want the entire bottom of my tank swarming with catfish. It's a personal choice. If you decide to stick with a lower number of them, it's better to keep just all of one type or two different types rather than doing a mix and match kind of thing. If you really want to mix them up then at least make sure they are all from the same family. Example: corydora