Hi Jason,
Currently, all the fields which are supported and available for exporting into Quickbooks are listed in the Manual. If you would like to receive a fixed quote to add any additional field currently not supported, please send an email with a link to this forum post to sales@smith-consulting.com.
Also, as a possible solution we are looking for a few clients to help test an new feature currently in beta development called Smith Quickbooks Connector which connects directly to your SmithCart store to download customer and order information from SmithCart and posts directly to QuickBooks. We are looking for at least 2 good SmithCart customers each from US, UK and Australia. Ideally, we would like to email a quick survey of options and possibly setup a separate forum to discuss the ways to make this add-on as simple and usable as possible. If you are interested, please email me at kevin@smith-consulting.com
Thanks,