Do you mean a hard case or a grip case? Hard cases are all relatively the same. Just get the size you would like. For grips I have had a lot of different ones. The ones that worked for my small hands were these generic brand silicone grips for games that don’t use the triggers often
https://www.amazon.com/dp/B089491N19/ref=cm_sw_r_cp_api_glt_fabc_W2C4WSR2F50M3FW84EWP
And the satisfye grips for games that do use triggers. I switch between the 2.
Another grip of note is definitely the skull and co grips for if you have larger hands but I should mention that the clear plastic shells stain and you have to buy from Amazon because the customer service on their website is awful. Hope this comment isn’t too late for you!