There are a number of Weight Distributing Bars from various manufacturers in almost every case they just distribute the weight from the rear of you vehicle to the front

Anti sway bars are another attachment that counteract sway.

 There is at least one WDH that is also anti sway this is the Andersen hitch which I have just recently fitted to my van but haven't as yet been on a long trip with it fitted. They are made in the USA

There was  South Australian company that made a combined WDH and anti sway bar but I don't think they are made anymore.

Cheers

David