I had a Sotz 55 gallon double drum heater for 3 years. You ask if it is a good heater. Hell, yes it is!
250,000 BTUs. A huge firebox, 32 inches long. Door is 11 inches by 11 inches. Good God can you load a lot of wood into that beast. Light it up with dry wood, and then you can start loading green wood, it will eat up whatever you put in there.
You don't want to use a grate. Just put 3 or 4 inches of sand in the bottom, to keep the coals off the steel.
In the spring, you need to take the stove apart, and clean it out, and spray oil in that bottom drum, to keep it from rusting. Just dump the sand out and replace it in the fall. After three years of heavy use, there was no damage to my barrels. I know Sotz guys who have used the same barrels for 20 years.
It makes me sad that Sotz is out of business because that was a great stove, especially for an application like yours, a shop where you need a lot of heat and you have a lot of wood. See, the modern stoves are more efficient, they get much more heat out of a given pile of wood, than the old Sotz did.
If you will dig around on Craigslist nationwide a Sotz kit will pop up every now and then, you can get one for about fifty bucks.
And what do you know, here are two kits for $175. I just dug this up on craigslist. One kit is missing some parts, the other double drum kit is intact and the package has not been opened.
(broken link removed to http://stlouis.craigslist.org/app/4853010813.html)
Send your money in now, this is your lucky day, this ad went in just yesterday and I bet it won't last long. You can get the barrels for free, all you need is a jigsaw with a metal cutting blade, and a drill and a wrench, you can build your wood stove in an hour. Plus, need to paint the drums with high temp muffler paint.
The all time bad ass wood stove for 200 bucks, plus you have a bunch of extra parts.
I now have a real pretty modern, EPA approved Waterford wood stove, made in Ireland. Cost $1,300 in 1998. Glass doors so you can see the fire. I like this stove. It is beautiful. Has a little Irish castle cast into the iron side. But, from the time you light the stove, it takes 45 minutes to start getting any heat out of it. Also, it demands really dry wood.
With the Sotz, you light it up, and in about 5 minutes it is throwing a lot of heat. Perfect for occasional use like you want. You need dry wood to light your Sotz but it will burn fine with wood that is not so dry. My little Waterford is rated at 45,000 BTU, about 1/5 of the heat output of the Sotz. Also, the Waterford throws good heat for about 3 hours, then you gotta reload.
With the big Sotz, no problem getting a 10 hour burn. Easy to burn 10 hours with that giant fire box.
Hell, I would buy this Sotz kit and intall it myself in my new house, but, the fiancee hates the Sotz! She has told me that she would leave me if I ever got another Sotz. I gotta shell out $2,400 for a new Jotul, glass doors etc etc.
Women, go figure. I love the Sotz.