Mobile Point of Sale System for a lottery

Small sized business seeking to expand its current raffles lottery into a lotto system. The requirements for this is a cloud based system used to store information from several mobile, point of sale devices that enable the clients to pick their number, in return at the exchange of cash, we need a system such that : i) The device can print a piece of paper that shows proof that the number was chosen ii) It can have a barcode that can easily be scanned to confirm that iii) All of this information, including the unique number, time of sales, (if possible, location) and the identify of the employee using the device, has to be sent up to the central, cloud based system that is secure and backed up iv) This is aiming to be in a small country with a (safe to say) 3g mobile speed network, so latency and queuing sending information up to the central database is a key consideration and issue v) (Optional) Even more advanced, if possible, the ability to read a filled template that users can opt to fill out their details in the case they lose their ticket.