I'm wanting to construct bins... under the trailer. The frame is I beams... I figure to put shelf on them which comes out to the edge of the body, with drop down doors. I'm not finding anything ready made. My rig is tongue heavy. I figure that to be a good place for items like wheel chocks, planks to level, wrenches & heavy tools (my 30T China jack). I think there's 6-8 feet of length there. I have to see if my welder is available.

Russ, have you thought about something like this? Look here: http://www.weatherguard.com/van_storage_equipment/view_products.php?Category=Specialty-Storage-Accessories&Subcategory=Itemizer-Drawer-Units

Yes, I thought of such drawers but don't have the depth from the side. Thanks for the link... it was a good read. I actually have an old van locking tool bin but I don't think it will fit. I'm going to measure. I only have one left. It is worth further investigating... I'd need to find another.I've stumbled on Weatherguard bed top toolboxes which could be mounted under the rear sides. Further research to be done.