According to your data, you have 1200# to put on your truck to max out the GVWR. You should not exceed GVWR. The important thing is the tongue weight which goes against the GVWR of your truck. GCWR is only a guide and should not be used to determine towing capacity.
You will not know what your tongue weight is until you weigh it. The manufacturer is giving you the dry weight of the trailer which does not include any options you may get or the weight of liquids. But remember that tongue weight should be 10-15% of trailer weight.
That said, the trailers you are looking at should be ok except the last one. You should allow for some extra weight capacity. Also, consider getting a lower gear ratio (a higher number means lower gear ratio) which typically gives you 1000-2000# of extra towing (but does not raise the GVWR).
Dan (RVM67), Yvonne & 2 nutty mutts
2015 Flagstaff V-Lite 30WFKSS; 2012 Sierra 2500HD Crew
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