Our 28RL is in that 600lb tung weight range (dry) and we are closer to 1,000 lbs. or maybe a little more.  I went with the 1,000 Equalizer bars because I want things to flex.  No point making the ride uncomfortable and no reason to stress the trailer.  Going with a hitch that is rated well above what you will be towing simply causes stresses to occur elsewhere, whether in the cab, or on the trailer frame. Buy a WDH for what your trailer is rated for and don’t go above because it does not add a safety factor.  My neighbor has a 28’ Sonoma that is a little heavier than ours towing with the same truck.  He’s been using an 800 lbs. WDH for six years and he really likes it.