As you are new, I'm guessing SkyPup was just giving your some good natured grief, but realize that towing capacity and tongue weight capacity are 2 different things.
The tongue weight is essentially the amount of DOWN force that is exerted on the trailer hitch. Most trucks cannot take a lot of tongue weight, which is why it is so important to center the load on the trailer so that it is balanced properly and not putting too much weight on the hitch.
As for the towing capacity of the Tachoma. I have no idea, but if Getut says he just got rid of his Tachoma to do essentially the same thing (and he has a smaller tractor than you do) then I'd suggest you are probably asking for some trouble?