I like your thinking! But like others, I think a WBDS is prolly out of the question... and coating the inside would kind of defeat the purpose... hot concrete is gonna stink. Warm smoky wine however...
But...
Lay it on it's side, Cut an access hole in one end shaped like a "D", put hinges on the flat edge to make a door (leave enough material around the access hole so that the end remains tight in the bands)
Attach a side fire box to one end with some sort of insulation barrier between them or a short piece of ducting, put a heat shield baffle in the lower 1/4 of it to redirect the smoke/heat, use the bung hole for a grease drip hole and call up swamprb to send you a few staves of his barrel so that you can make a mini chimney (even if you have to use pipe inside and just use the staves to give it the finishing touch).
Lastly call
this guy to have him make a Rib-O-Lator that will fit it. With a hole drilled in the fire box end you should be able to attach a rotisserie bracket for the motor and pass the other end of the rod thru a small hole in the door
Now the problem you will have is keeping the wood from drying out and allowing the staves to loosen, you might be able to use a heat gun and some parafin wax to melt wax into the outside to give it a sealant that isn't going to affect flavor. Heck, the wax will probably darken up that color a bit and give you a nice polished shine too!
If all else fails and the thing just isn't going to come together, you can always use it for smoke (unless you wax it, then your Q will prolly end up tasting like Tony Roma's or some crap, but hey! What else is all that sauce for??)
Hmm, now I need to find a barrel... my wife is gonna kill me.
Now smoke if you got em'!