Reese Dual Cam Size with a toy hauler???

The gross weight rating of the trailer is 11,000
the 1200 of the dual cam would cover the gross weight, but not the tongue weight if it's higher, but that's ok?

Then use 11,000 as your gross weight target for sizing the hitch. You will be fine with the Reese at 1200/12000 behind a one ton truck. The 1500/15000 might be better if you are loaded all the time as 11,000 gross usually puts the tongue weight around 1400 pounds. Behind a one ton the need to distribute any weight is minimal or not at all so really you are looking at the sway function of the hitch. Be sure your stock receiver is rated for the weight of the tongue. You may need to go to an aftermarket receiver to get up to around 1500 pounds capacity or greater. All is doable. The Equalizer hitch mentioned by another is purely a friction based hitch and does not work the same way the Reese works. The Reese is better but does take a few minutes more to set up. Once set up you should be good to go.

Remember, if you are not carrying the toys the tongue weight percentage goes up but the overall trailer weight goes down so the tongue weight change empty to full issue might be offset and not be that big of a deal. If you are going from 11,000 with toys to 9300 pounds without toys and the hitch percentage stayed the same the reduction would be about 200 pounds. Your hitch percentage would need to increase from about the rule of thumb of 13 percent to 15 percent to be at the same 1400 pounds tongue weight. This change is very doable with the hitch you are selecting and a one ton truck will do just fine with 1400 pounds at the hitch. Weight distribution hitches redistribute about 20 percent back to the trailer axles so you are not adding the full 1400 pounds to the truck's axles.