PHP/MYSQL Database

My company is currently working with an online database called FurnishWeb and Dabble. ? We are trying to incorporate the same mysql or php database that those companies are using, but in our own website. ? What I need is the following: -A login for both Sales reps and Admin Users -A way to create inventory records -A way to input customers and then bill customers to a default invoice style sheet -Uploading of pictures to match the inventory products we are creating -A simple way to import and export files to and from excel (to make updating the database easier) -a very user friendly style This database needs to be fully integrate into our website that is currently under construction. ? If you visit the sites that were listed about you can get the general idea of what I am looking for but much more elaborate in the scheme of things when it comes to implementing more of a customer relations manager, invoicing, and inventory control all into one database.