Biggest difference is my drawer system will also hold 3 1lb tanks. I'll have hosing routed with a valve. The sink drain will be a piece of 3/8" hose that will come out of the small hole to the lower left of the tanks with a 90* adapter, the ~30 piece of hose will simply fit in the slider's space when the drawer is pushed in and fall towards the ground when the drawer is pulled out. I'll keep a longer hose and barbed connector if I want to route it elsewhere. I'm also considering using 1/4" Loc-Line that will fit in the same space, the Loc-Line would be nice because I can bend it and it'll hold its position until I stow the drawer. However, 1/4" will drain slowly and get clogged easier, but I will be using a screen filter trap in the sink.
I'll also have fold out supports for another horizontal surface
First drawer is 36", then 24", then 22". I'll be using KV 500 lb Slides for the first 2 and smaller KV 150lb slides for the last section. I've used these before and they are great. I'll be removing the lock-in feature from the large 2 slides and just using the latch, the lock out will still work. All size slides are lock out to eliminate the driver/passenger swaying like you'd get with just one lock out.
I plan on keeping the drivers and passengers drawers separate so I can remove them as needed. The fridge and MSA slide will be able to be mounted on either drawer. The cargo drawer will have a sliding cutting board that can be accessed when the drawer is partially opened and I can remove it if I don't need it.
My main water source will be 5gal Jerry cans, I've had larger mounted tanks in other vehicles and they were too hard to fill on the go. I'll have one mounted between the box and the drivers side rear bulkhead just behind the wheel well with a spare on the passengers side. At this time I don't think I'll plumb into the one on the passengers side, I'll just siphon from one to the other. Having an easily accessible jerry can on the passengers side means I can remove it and fill it easily. I'll use a 3/8" hose that is permanently connected and will simply pull out with the drawer and push back in when I close it, no need for water hook up with each use. I'll use an small automatic hose reel if it doesn't stow correctly on its own.
Thoughts?