Customize a wordpress plugin to manage human translation services

Hello, I would need somebody to help with a wordpress website to be used for human translation services. The person that will take this job will need first to choose a free wordpress plugin and then to customize it to be able to manage in the most efficient way the requests for translations. When everything is ready it should also be published online. 1. The customized plugin should work so that a customer submits the document to be translated and pays via Paypal. Based on the type of translation purchased (standard or urgent) the customer will see the estimated delivery date. The translator upload the translation via the control panel. A notification is sent to the customer that can log into the platform and download the translation. 2. The translator should have a view in the administration panel of the list of translations ordered (one per record), plus possibility to view the file to translate 3. The customer should be able to see the status of his order after login into the platform 4. The platform should for the moment accept only paypal payments but should be able to be interfaced to the Stripe payment system in the future. More information about the design later or on request. In order to be considered for this job, please suggest what plugin(s) you would considering using and how you think is possible to interface your solution to Stripe in the future.