I can't recommend any software, but I do have a couple suggestions.
1. Connect the two computers to the same LAN using ethernet, not wireless. Using file sharing connect the mac to the PC and drag and drop everything you need.
2. Get an external hard drive, create some folders for the types of files you will be transferring and copy away.
3. Put the hard drive from the PC in to an external enclosure, connect it to the mac and copy.