Build some custom functionality into an online survey

General information for the business: We run customer satisfaction surveys for companies
Kind of development: Customization of existing program
Description of requirements/functionality: I'd like an online survey customised or built from scratch which allows me to compare the results of one group (ie those answering 'A' to a question) against ALL other respondents. There are plenty of off-the-shelf surveymonkey type applications which allow me to compare A to B, but I want to compare A to A to G so I can benchmark A's performance against all respondents.

Also, the output results graphs need to look good too, and preferably allow some branding to be incorporated.

Can you help? Let me know and we can chat more...
Extra notes: General information for the business: Online customer satisfaction surveys
Kind of development: Customization of existing program
Description of requirements/functionality: I'd like an online survey customised or built from scratch which allows me to compare the results of one group (ie those answering 'A' to a question) against ALL other respondents. There are plenty of off-the-shelf surveymonkey type applications which allow me to compare A to B, but I want to compare A to A to G so I can benchmark A's performance against all respondents. Can you help?
OS requirements: Windows
Extra notes: We don't have to work together in the same office, but meeting occasionally would be good as there will doubtless be ongoing developments I would want. So being based in the UK and preferable the south west of England or in London would be great.