Hi David Payerle - I don't know whether Jennifer Comisford wants it but I'd love to see that code if you're interested in sharing.
However, I think using JS to do a data lookup (client side) and then using that data to manipulate the form (also with JS) is probably the simplest approach. There is an interface in the Eloqua app for creating data lookups and I think most people will find that easier than using the API. I would advise doing the visitor lookup first (that way you get whatever visitor profile they're currently cookied with), get the search data and the email from that, and then if necessary use the email to do a second data lookup to pull the rest of the data you need from the contact record.
Having said that, I expect your approach will work too.