According to the information I found it looks like your trailer is equipped with tandem 3,500 lb axles so for replacement brakes I recommend the Electric Trailer Brake Kit # AKEBRK-35-SA which has self-adjusting brakes. Once you perform the initial installation and adjustment they will keep up with the self-adjusting so you don't have to manually get in and adjust them when they are weak.
If you have different axle capacities let me know and I can make a different recommendation for you. view full answer...