Drupal Survey and Reporting Tool

We are looking for someone to develop Drupal-based survey and graphical reporting functionality in Drupal 6. The output report is an analysis of corporate risk based on the survey responses. In a nutshell, users would complete a multi-page survey (next page functionality required). At the conclusion of the survey, the user would hit "submit" and be prompted for login/registration. Once the user completes the login/registration process, he is presented with an output report based on the results of the survey. The survey is modeled in Excel. The calculations involve nested if-then statements as well as MAX functions (among more basic math functions). Here's a step-by-step process: 1) user fills in demographic info in section 1 of survey 2) employee count in section 1 segments user as small, medium or large company 3) segmentation is relevant for scoring b/c different scoring rules apply to different size companies 4) at the end of each section, the user is allocated a score - this score is turned into a percentage, which becomes the basis of the risk score. So, for example, if a user scores 40% in the business risk section, his company will have a high business risk. Here's what I'm looking for in terms of development: 1) survey questions to be set out in survey nodes on our site, but with questions spread out over two or three pages - we will need 'next page' functionality. Our website already has an enabled webform module. 2) upon final submission, a report is autogenerated with graphical display of each section's risks, together with some canned text that is triggered by the specific response. I’m thinking that the charts should either be thermometer or gauge. The user should have the option to download a PDF version of the report 3) user is required to register/login. Our website already has registration/login functionality 4) we would like to aggregate the survey data for future purposes 5) we would like the model to be scalable to add additional survey/report tools in the future I can provide a sample of the in-progress model upon request.