Check the rear axle weight limit and the limit on your tires. Also, manufacturers usually take into consideration that the driver weighs 150 lbs and a full tank of fuel. I am not one to recommend going overweight but an engineer friend at Ford says they set the limits based on what 80% of the people would feel comfortable. The first trailer you mention is what I would go with. Not sure how much gear you will load but I NEVER tow a tank of freshwater...at 8lbs a gallon it adds up fast.
There are some here that swear you need a dual wheel pick up to tow a pop up. When you talk weight limits, you are opening Pandora's box on this site. I think most will agree the truck will be more than fine for the smaller trailer.
