I have a work for the college that consists in making a virtual business (Create a service or a product, basic implementation and economic study).
The business consists of a method of payment using Rfid bracelets, since every Rfid Reader needs to be connected to the remote database I need to know the hardware, software, that best fits this model. For around 50.000 people with an account in our system (with client balances, historical, personal data) and for 500 Rfid Readers connected to the server what is the best option? Good security is vital, email and software hosting comes in handy for updating purposes. Redundancy is important as well and I need to have an idea of the maintenance issues and costs.
Since I'm a newbie in servers (I'm studying electronics not informatics) please don't get over technical.