There is no FTP option for uploading your images at this time. If you are having trouble with doing it via Pro, you can always manually dump all of the images into the Pro image directory, then open the program and synch.
C:\Program Files\Vendio\images
Or
C:\Program Files\Sales Manager Pro\images
Or
C:\Program Files\AuctionWatch\images
Depending on which version you have, this is how you can navigate to the images folder directly to simply dump or copy all of the images you want to upload directly into the program to upload the next time you launch/synch.
Note that while this will work, it will also allow you to add images over the 350k limit, and the synch will fail when it gets to that image, requiring you to go in and remove it before you can finish the rest of the upload process.