Inventory-System need some changes - php html css database

Hello Freelancers, we have an inventory-system: [login to view URL] Here we need some changes and addiotnal features. Please ONLY PROFESSIONAL and experience porgrammers. Thanks. First Step - toDo List: 1) /add_product/ ---> Product General Price --> need table "Amazon total fee" (Note: Fill in by ourself) --->Product General Price --> need table "Buying Price CNY" (because we buy in China and it have other currency) ---> Product General Price --> "Buying Price €" (Note: calculated by itself) ---> When i fill out into "Buying Price CNY" the Buying cost, the table "Buying Price €" should be calculate automatically ---> Add currency settings also in 'Settings' (i will change it everyday the currency from CNY into € - actually is 1€ = 0,14 CNY) ---> Calculte example: I fill in "Buying Price CNY" 10 CNY then calculate like this (=10 CNY * 0,14currency rate * 1,14 duty customs = Buying Price €") --> So the "Buying Price €" is fill out automatically --> Product General Price --> need table "Profit per item €" (Note: calculated by itself) ---> Calculate like this: (=("Selling Price €" / 1,19tax ) - "Amazon total fee" - "Buying price €") ---> "Special Offer" and "Tier Price" make it invisble 2) /product/manage_product/ --->invisble the table --> "Code" ---> add "Product Name" (maximal lenght should be 20-30caracters) and then follow with … ---> add "Amazon inventory" (Note: get the inventory qty from Amazon - we will have 2 inventorys, 1 our own warehouse and 1 from amazon warehouse) Own warehouse we use your system, amazon qarehouse qty you can take from API) ---> add "Profit per item €" ---> add "Selling price €"