Caution about looking at trailers listing 500lbs for the trailer hitch/tong weight. Be leery about advertised Tong/Hitch weight which is the generally the minimum weight.
Example my 21DS (22'4”) Flagstaff Micro Light has a Hitch Weight Listed as 614lb. Recently when I weighted my Rig at the scale, lightly loaded (684 lbs) in my opinion, for me and my wife for a 1 week stay. My Hitch/Tong weight computed to 740lbs. Also, I DO NOT Carry Water in my 52. gal Fresh Water Tank. My camper comes in at 4,841 lbs empty with a maximum Cargo Capacity 1,933 lbs.
A good rule of thumb is take the MAXIMUM Weight the camper can handle times .13% for a maximum expected tong weight to be subtracted from your trucks CCC (1,800lbs as you stated) which gives you how much Capacity you have left for passengers and gear.
So using my numbers, Camper 6,744 lbs (MAX Load) * 0.13% = 881 lb tong weight. Add another 100 lb for weight distribution hitch brings the total to 991 lbs that needs to subtract from your cargo carrying weight, 1,800lbs – 991 lbs = 809lbs. Caution 4 full grown size men could easily weigh 809 lbs
Sorry I didn't answer your question about a equalizer, I'm assuming a WDH (Weight Distribution Hitch). Currently I am using a Andersen WDH, which I'm on the fence about recommending.