So I'd very much caution against requesting SSN and/or credit card data in Marketo unless you've setup SSL and are taking other security precautions. I had a client accidentally sync SSN field to Marketo - VERY BAD risk.
If you are sending this to 3 people, perhaps it would be better to call them up instead.
Google Forms and SurveyMonkey are a couple good 3rd party apps that do this better at scale.
Since you're doing it in Marketo, creating a custom smartlist view that includes the fields in your survey and exporting the results to Excel is probably your best bet as Josh said.