Thanks.
I haven't had good luck with stock radiators in XJ's, even with the heavy duty cooling setup. The core just isn't big enough for the small amount of surface area that the XJ has, especially if you start towing even close to the 5000 lb. rating up a good hill. I usually use Griffin radiators, they use a cross flow core and fitment is always spot on.
The cargo area is my biggest conundrum. I have figured out a good water storage setup for the rear footwell area and the compressor and water pump are going where the factory jack was stored so I'm good with that. The drawer situation for the cargo area is probably going to be based on 2 ARB drawers (one with roller top) and then I'll build in the side fillers to hold the 12v inverter and other misc.