I need to carry a lot of personal belongings cargo and keep it dry. More than will fit in the bed. I have an inside the rails hard cargo cover that is rated to hold 400 lbs evenly distributed. I am considering buying a truck bed cargo bag and strapping it down to bull rings in the stake pocket holes. I can't imagine the cargo being more than 150 lbs like blankets and the lighter stuff. I can't seem to find anyone on the internet who has tried this. I am only going to need to do this for a year so I am not looking to make a major investment. Does anyone see serious issues? Any better ideas? Any way to make this more secure?