Convert Small Windows Application to Mac Application

We have a Windows application that is used to update a firmware in a custom USB device. The application is written in Delphi 2007 and we have complete source code, as well as the source code for the USB driver. We need that application and its driver ported over to Apple Mac OS X platform. The deliverables would be the compiled application for Apple with an installer, and source code for both the ported application and its driver. Compatibility with various MacOS X systems is TBD, 10.4 and up is ideal, 10.5 and up is acceptable.