Thank you for the pictures!
To fit your 4400lb Lippert axles you will need Electric Trailer Brake Kit - Self-Adjusting - 12" - Left and Right Hand Assemblies - 5.2K to 7K # AKEBRK-7-SA which will replace the Lippert 122259 brake assemblies you have.
To verify which hub and drum assembly is correct for your trailer you will need to remove your hub and drum assembly and check the outer bearing numbers. If your bearings are worn to where you can't read the numbers, you will need to measure... view full answer...