I have a 10k rated, 10" adjustable drop reciever. Paid 68 for it.
I also have a 12" plate reciever with the duplex ball/pintle. My duplex is rated 8ton w/2 5/16" ball but you can get 6ton w/2" ball also. I guess you could say I would have made a good boy scout.
I know you can also buy weight distributing setups that include an adjustble (Hi-Lo) reciever bar.
If you need more info or explantion, let me know.