There is a company by me that make all kinds of tool boxes and truck boxes they are called Highway products i am going to go talk to them and see if they have any ideas . also there is a place that builds Fire engines that i go to alot i will talk to them and see if we can come up with something . The hardest part i think is going to be the lid and trying to get the bed floor to work . My idea is to kinda make a box that would look kinda like a sink if that makes sence ? If i go with aluminum i am not sure how to mount it ? if i go with steel i could weld it to the bottom of the bed .