I can confirm that Form Wizard Pro does not allow you to change the form action and does not have any integration with Salesforce.com. Integration with SalesForce.com is on my long term radar but nothing I expect to get to soon.
For now the tips Joe Davis suggested are probably best or else create an html page and host it in an iframe from inside the mojo Html feature. You could paste in the iframe with the url to your html page using the html view in the editor.
Hope it helps,
Joe