flat bottom for both. There are actually 2 coffee makers, a small one and a larger 10/12 cup one. Your standard flat bottom filter will work in the big one, we drink a lot of coffee so never used the little one! Definitely bring your own coffee and you will need to bring filters as well. I'm sure they sell them at the trading post...at a premium!
FYI the coffee cups themselves are on the small side, we treated ourselves to new trip mugs and used them everyday! L(