Master Detail Database Web Application

I need software to manage my cellphone repair shop. Eventually, I would like a full blown system which can handle inventory, billing, etc... but for starters I just want to have a system which will keep track of customers and work orders. Pretty straightforward. Tables to manage customer information and the devices which they drop off for repair, a clean user interface and the ability to print customer receipts. That's it. If you have experience with this type of system then the database schema might come naturally to you. Otherwise, I can easily design the database according to your specifications and my needs. I can also provide guidance on what I think the interface should look like but your work will probably be better than my ideas. I would like to be able to access the system from any computer so a Web Application seems like the best approach. In your bid, please specify what technologies you will be using and provide whatever demos you might have. Please don't hesitate to contact me for more details. Thank you!