There's a lot of options out there with new ones coming out every day.
But I think the key point you'll find is that one program won't do it all. POS systems are more business management systems that cover business operational issues such as cashiers, inventory, sales, etc. These systems usually have daily reports with numbers you can then either export or manually enter into a back-end accounting package. From this package, you can manage more of the financial side of the business--write checks for bills, make entries for AR/AP, assets, etc.