Wordpress development - multi step questionnaire

project consist of 1 questionnaire
wordpress website is already active and in use (so no upgrades/downtimes or what so ever please)

8 steps need to be filled in by the user
in every step about 1 to 5 questions need to be answered
in about 4 - 5 steps user will have to upload files

result should be a mail with
- all questions answered by the user
- links to the files the user uploaded
- clean layouted mail with all data / info included

coding should be done in a clear / clean & proper way (so nog 10.000 lines copypaste)

price is fixed and in this price, 2 full revisions should be possible: 1 after delivery and 1 after 1 month of live-inuse of the form