Automate PIN delivery (Website)

Hello, I would like to create a website that automatically delivers phone card PIN codes. The website should have several buttons (multiples of 5,10, 15 up to 50 USD) and an option to choose either PayPal or Google check out. The front page will have a massive table with country rates. The entire website could be just one or two page. What I want to have: 1. Easy interface to upload PIN codes with a spreadsheet. Card values as I mentioned will be 5,10,15 ...50 USD values. 2. Ability to change prices easily. 3. It has to be safe for my customers.