25contender, That is some good looking work. I was looking at something like this but I just couldn't picture putting a dead deer on top of it and having it bleed all over my gear. Looks like your pretty good at "honey do" lists.
I have a rubber mat that fits on top. and all my gear fits in the boxes. I also have a carrier that fits in the receiver that was made so it is about 2ft off the ground so it doesn't hit anything in rough terrain. You cant see them but there are 4 hatches that open up in front and in back of each wheel well for extra storage. I think the whole project was right at $300. It can be lifted out if it needs to be but I have never taken it out because I use it all the time. Makes neat lockable storage and you can still use the top of the boax for other gear and sleeping.