Any major WDH will work. Just make sure you know your tongue weight ( go to a CAT scale preferably ) or estimate 12-15% of total loaded trailer weight for tongue weight. Just be careful of your payload and understand how that works (usually you run out of payload before towing capacity). 6000lbs seems like you could be pushing that truck depending on what you have loaded down in the tow vehicle. (Not that the engine couldn't do it, just close to your GVWR) I personally have the R3 1000 WDH. I like it because there are no chains, the sway control is built in not on a side bar, and its quiet, like zero squeaking or creaking.