Newbie needs help on a build question please!!!

Converting a refrigeration unit into an oven can be an expensive task....  You could use it as a cold smoker no problem....   

I would replace the compressor and have a cooler, fermenting chamber for pancetta, brasciola, etc.... Stuff that takes months and needs lots of storage space.... fermented kraut, kimchi, dry aged salami .....   

Hokah, I don't know what to tell you about the remodel.... A recirculating fan for heat / smoke will be needed in that size smoker whether cold or hot smoke is used... I'm not sure how well an external firebox would heat the cook chamber....  There is a lot of heat loss using an external FB...  Fat dripping from meat is a real fire hazard....  I had a smoke house catch on fire... it was a concrete block with external FB.... I lost 200 #'s of salmon... smoker was OK...  Fat from salmon burns real good... and hot...  once the fat hit the smoke stack the temp started going up... the higher it got, the more fat dripped.... a never ending cycle and I was standing there watching.... by the time I closed all the dampers, took about 30 seconds, everything was toast.. 

Check around commercial smokers.... see what they do...  I worked at a commercial smoker doing their welding... their smokers were heated with high temp, high pressure steam...  not much chance of fire using steam...  

My friend did commercial smoking...  built a smoker totally out of steel... It was about the size of your cooler....   He had a fire in the center of the floor....  It was about 18" x 24" steel box suspended under the floor on rails.... he pulled the firebox out, added a split or two and slid it back under the smoker....   That was a cool design and worked very well... with long remote therms you could keep track of temps from outside...  some type of baffles would be needed for the fire... mild air recirc would be needed....  replace the wood floor with steel joists and flooring....  A couple grand and you would have one dandy smoker able to hold 1000#'s of meat...   a lot cheaper than some small smokers on the market now....  My friend designed some very unique meat hanging equipment in that smoker....  he was a steel fabricator all his life.... his wife ran the smoking business from home for small butchers and home sausage makers....   If you decide to build the smoker, I have more ideas to help you out.... or convince you not to do it...

Dave

And if you want to bring that walk in cooler back to it's original purpose without spending a ton of money on a replacement compressor, check out the Cool-Bot.   They use an external controller to convert a window A/C unit into the source of cold air for a walk in cooler (sort of like the way we use PID's to run heating elements in a smoker, just to cool instead of heat).

http://www.storeitcold.com/

Here is a video of how it works & the install (about 2 to 3 minutes to install one)