Restaurants cloud SAAS POS

I'm looking for a cloud-based SAAS POS system for restaurant business. I need the POS to be able to handle payment processing, as well as other features related to inventory management and table reservations. It will need to be able to integrate with any other existing software that I may already have, although I'm not sure which ones at this point. The POS needs to handle more than 200 restaurants, so it should be equipped to handle a sizeable workload.