We're working on a custom development for this right now. Essentially the concept is:

1) Have a normal, non-LF HTML form with Forte payment inegration, that pushes all values to a database with a submission time stamp

2) Have a workflow run on a schedule once daily to grab all entries submitted the previous day and invoke a business process with the data on the table mapped to the correct forms variables

We ran into some difficulties with including attachments but got around it with Import Agent and workflows.