First welcome i iRV2.
In order to find out what you can tow with your 1/2 ton truck, you will need to get the truck weighed in travel trim with all pasengers and normal cargo and full fuel. Call this your Laden Vehicle Weight or LTW.
Now, in th eowners manual you can find towing ratings and loom for the GCWR or Gross Combined Weight rating which is the most your truck and trailer can weigh together. Make sure you use the information specific to your particular style truck cab, engine and axle ratio.
Now look on the drivers door jamb for an information sticker wich list your GAWR (front and rear) and the GVWR (Gross Vehicle Weight Rating) which is the maximum your truck can weigh with all cargo, passengers and tongue weight from the trailer.
With this information...
GCWR - LVW = maximum loaded trailer weight.
GVWR - LVW = maximum loaded trailer tongue or hitch weight.
This is the only way you will know for sure. The manufacturers tow ratings are a maximum and based on a stripped base model truck with only a 150# driver.
Personally, I would not try to go over about 25' (actual trailer) with a 1/2 ton truck. I doubt if you will find a queen bed plus bunks in that size trailer.
We have been the rouut of pulling too much with too little truck and it is not fun for long trips. If your truck is rated for the weight, you might go up to a 27' trailer, provided you are not over weight and fro shorter trips of 2 to 3 hours.
remember that the brochure weights for the trailers are fiction. A dry weight does not include anything listed as an option; such as A/C, microwave, TV, awning batteries, etc. You can easily be 500 to 750# over the dry weight before you add anything of yours.
Have fun shopping and do not believe anything the dealer tells you.
You will find two types of responses. The best provide real information and weights if they are telling you that they pull an XX' ABC brand trailer and then the other is the passionate post with no information other than it pulls it like it was not even back there.