You'll need the flat bottomed filters, similar to the Mr. Coffee brand.
Studios have a 4 cup maker and the larger units have a 12 cup maker. That said, if you need the larger maker and you are in a studio, you can call Housekeeping and they will bring you the larger size.
Many guests like the combination coffee/filter packs (I believe Maxwell makes them and I'm sure there are others). With those, you don't need to worry about the filters. However, others (like me) prefer to bring their own brand of coffee and since it doesn't come in the filter packs, we need to bring filters as well, LOL.