Developer for Multi-lingual Questionnaire/Poll Website function with PDF generating

I'm looking for an experienced PHP website developer to create a website function framework with a unique functionality with these moving parts: 1. A questionnaire that collects answers in a database on 20-25 questions in up to 11 categories (see example). 2. Collect payment and e-mail address. The a-mail address and answers are linked to each other. 3. Calculate a score between 1 and 5 for each category (this module should get the answers per each question, but we will program the logic for this ourselves. For testing purposes it's okay to randomly score each category with a value between 1 and 5). 4. A PDF is generated with multiple pages: a title page, a radar graph (see example) and blocks of text with explanations (it's important for us to see how the PDF will be generated, with a radar graph embedded in it and extra blocks of text) Please check out the use case document I have prepared for this. It's important for us to have a framework from which we can flesh out and work to finish the questionnaire and generated PDF ourselves. In other words, the basis must be there, after this we will continue the development towards the finished product. Key Features: - Multi-lingual (we start with English and Dutch, but we want to be able to roll this out in other countries, other languages) - Processing of payments before generating a PDF - Generating PDF with Radar graph Requirements: - Great PHP programming skills with database driven content. - Able to program cleanly and structured, with good documentation. - The function will eventually be integrated within a wordpress site, so knowledge how to integrate is a plus. - Experience or understanding of e-payment systems - Knowhow in how to generate PDFs with integrated graphs - Skills in translation are a plus, but not necessarily required - Using open source functions to speed up development is expressely allowed and encouraged. If these are licensed/paid functions, we are open Your responsibility will be to design and build this website function framework, integrating the mentioned features while ensuring user-friendly backend management. Please bid with samples of similar projects you've completed.