Add point of sales features to my CakePHP portal

I have a business inventory portal it is established and built in CakePHP. I need to have some additional features added to it so that I can make over the counter sales to customers. When a customer buys items from me, I need to print a receipt to give them and store the details of the sale and the customer. I need to be able to do the following: Have a new Sales category in my portal. Complete a form and add multiple items being sold from my inventory by name or sku, customer name, address, email etc, date of sale etc. Item lookup by text search or SKU. Add pre-configured tax to the sale. Allow manual entry of items sold even if not in inventory. Allow notes to be added. Add payments received by customer. To show employee name. Able to print a copy for the customer to keep. Items sold must automatically deduct from current inventory. A return process and form to bring returned items back to inventory - item by item - printable receipt. All sales to have unique sales numbers on each. All returns to have unique return numbers on each. Copies of each sale and each return must be kept so they can be printed later. A folder for each list of these. Report to show sales by product by any period - printable and exportable to CSV. Report to show sales by employee by any period - printable and exportable to CSV. Report to show taxes taken by tax, by any period - printable and exportable to CSV. Report to show returned items by any period - printable and exportable to CSV. Report to show payments received, by payment, by any period - printable and exportable to CSV. I must be able to review all features added and the programmer be prepared to adjust anything as needed to have it right for me. Any bids on this project needs to include examples of other CakePHP work and point of sales work completed.