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.

Thanks in advance.

What have you come up with so far?

I'm exploring Microsoft BizTalk Server, sounds interesting. Ground Zero besides that.

How detailed do you need to be?

If you're working at the conceptual level it's quite possible that you can get by with simply laying out the overall architecture without getting all the way down to a specific product.

Don't need detail. Just the overall architecture as you mentioned.

Have you look into amazon ec2 and other amazon services?