PHP + MySQL web-based project

The idea is to programme a very small electronic store for subscription for some goods. Here is what must be implemented: 1) the customer choses his good in a very narrow assortment of goods, subscription type, the terms of delivery, his contact details, and payment method (he goes through 4 or 5 consequent pages). 2) the data user leaves is stored in MySQL database on the server. I must have an administrative page for viewing and editing those entries in a database, changing the status of the order. The customer must be able to log in later on and view the progress on fullfillment of his order 3) all pages must support two languages. This should be implemented as reading entries from two files (English and Russian). If you don't speak Russian, no worries, just make sure the pages can be switched into a second language, reading entries from separate file with same words, which I'll be able to change into Russian myself. 4) the PayPal payment interface must be implemented - I will supply the required data for this interface. 5) The graphics and design for those pages is not part of this engagement, so just functionality must be implemented. However, everything must be written in clear and concise manner, so other people could understand and change the code later on.