This part that you are looking at has two weight limits tongue and trailer.
You need to get one that will cover the weights of your toad. Your original question was only asking about tongue weights. We were informing you that you have to consider all weights.
The 100lb tongue weight one may only have a 1000 pound trailer weight rating and your toad weighs 2800 this would not work.
The 500 lb tongue probably has a 5000 lb trailer weight limit, this would work.