On the hitch size. A 7800lb dry trailer will weigh at least 9500lbs loaded for a trip. That would give a properly loaded tongue weight of 1200+ lbs. the 1200/12,000 lb hitch is necessary.
At that weight no hitch is going to be quiet. You will get some popping and screeching!
Not familiar with your hitch either. I ran a Reese 1200/12,000lb Dual Cam (centerline) hitch. It made noise but wasn't bad. My suspension was far noisier than he hitch until I rebuilt the springs with bronze sleeves and wet bolts. After that I could pull into a campground with the WD still engaged and it was quiet.