You should consult a personal injury/accident attorney in your area to review your case and determine your legal options. From the information that you give, you should probably sue both the owner of the vehicle and the driver. The owner is liable for allowing an unlicensed driver to driver his truck. The driver is also liable since he caused the accident by hitting you. There is also the issue of the owner allowing the driver to use his vehicle in a work situation (farm truck). There could be other liabilities for this under both Iowa and Nebraska law.