Word press registration form problem

We have a registration form on a Wordpress website which asks the client for a lot of information. We find that to ask for this amount of information in one form is too much, so we need to set up a system where the client can put in basic details , then be offered another form (Page) to complete more details. This scenario would need to be repeated several times to complete the collection of all the information required . The problem is I need a way of the client being able to fill in part of the form save it and then come back later to complete the next sections until it is complete or they are prompted to submit what they have done The website is using a Wordpress theme Directorist and at the moment we are using contact form 7. but this looks basic . I've looked at other plug ins and it would appear there are several that will produce the kind of thing I'm looking for , but as I don't have time to learn how to use these I'm looking for someone who is experienced and capable to produce a form that integrates with the theme.